The master for this FAQ is now the HTMLized version. The current version of the FAQ can be fetched from http://scifi.squawk.com/scuba.html. If you are reading a text version of this FAQ, it was prepared by running the FAQ through lynx -dump http://scifi.squawk.com/scuba.html. New email addresses for scubasearch were added on 25 April 1995.
A question on GPS was added in July, 1995.
In October, an EPIRB question was added, and a new mail-to-news gateway was posted. A comment about commercial postings ws added as well. The charters of the subgroups were added in August, 1996.
Please feel free to follow-up with comments or email them to firstname.lastname@example.org.
Where should you post? There have been two subgroups of rec.scuba formed. If your post has to do with equipment, consider posting in rec.scuba.equipment:
Before posting to this group for the first time, please check the FAQ list (this posting), and also read the newsgroup news.announce.newusers, which contains many answers to questions about usenet in general.
Are you a new poster? Or an old poster who frequently gets flamed? One-to-many communication on mailing lists or newsgroups is a lot different from the sort of communication you are used to. I strongly recommend the reading of ftp://ds.internic.net/rfc/rfc1855.txt for general guidelines about what and how to post.
Finally, some dives are just plain more dangerous. Your certification course should have trained you to recognize your limitations, or, conversely, to recognize the sorts of diving you were trained to do.
Various people who post to rec.scuba discuss advanced diving. This stuff is just a discussion. It is not meant to be a replacement for a certification course with an instructor, and it is not meant to be an encouragement to you to go out and engage in similar diving without evaluating your personal skills, and/or getting the appropriate training and equipment, as required. Specifically, Cave or Wreck or Deep diving requires advanced equipment, training, and a careful self examination.
Finally, it should be obvious that not everyone who posts their opinions to the net is or can be (a) an expert or (b) correct. It is likely that your instructor, for example, would disagree with a number of the points of view expressed herein, and would probably disagree with part of this FAQ.
The fact that someone who identifies themselves as an instructor posts to rec.scuba does not create an instructional situation.
This question has frequently come up in rec.scuba. One of the discussion threads has been summarized as whosbest.txt in the rec.scuba archives at ames. See the explanation of Peter Yee's archive, below, for how to access the ames archives. The short, widely agreed answer, is that agencies all must follow a minimum standard set by an industry organization, so they differ less than you might expect. However, instructors differ a lot, and you should try to talk to the instructor you will be taking the course from and determine exactly what will be offered, and how you feel about them. Finally, some instructors add significantly to the standard course (and may also charge more). You should ask exactly what you are going to get for your course fees, what else you will have to buy, and where you have to buy it.
There are two schools of thought on this. One is that you should consider only purchasing your personal gear until you are sure what type of diving you like. This school believes you should buy only mask, fins, and snorkel, for fit and sanitary reasons. The other school of thought is that the rental gear you can rent, especially in tropical locations, is second rate and poorly maintained, and that gear you purchase will be better and more reliable. Typically, people agree that you should not buy a tank until you believe that you will be doing a significant amount of local diving.
The purpose of a FAQ is to answer commonly asked questions which have answers that can be agreed to by the majority of the group. There are many conflicting opinions on mail order that have little to do with scuba, and, after long consideration, I felt that it was impossible to write a mail order question answer that was informative, covered all views, and which generated more light than heat. I suggest a scubasearch with:
Subject: mail order
before bringing it up again.
It is my personal opinion that if you are asking this question in this group that there is a very good chance that you do *not* have enough knowledge or skill to safely purchase either life support equipment or equipment ancillary to that, and should reconsider doing so.
There are two rec.scuba archives. The first, and oldest, is maintained by Peter Yee. Peter has collected travelogues, equipment reviews, and so forth into pre-organized files. In Peter's own words:
You can also use the SCUBA archives on ames.arc.nasa.gov. Send mail to email@example.com (or ames!archive-server) and use a subject with a line like "send scuba index". This will get you an index of articles in the archive. They are sorted by subject and you will that you get pretty much what you ask for. To get Florida info, try sending a subject of "send scuba florida.txt keys.txt". -Peter Yee firstname.lastname@example.org ames!yee
Advantages to Peter's archives are that they are organized by subject, allow instant access if you have FTP, and are actually about the subject in question rather than just randomly containing that word or phrase. Follow this to the ames archive.
The second archive is maintained by (me) Nick Simicich. This is sort of a minimalist archive. There are over a years worth of articles in the backlog, and you can run an "egrep" against them and the responses will be organized and sent back to you. To use the archive, mail to email@example.com (if that bounces - a correctly operating scubasearch might take hours) firstname.lastname@example.org.
You can also run a scubasearch through the web if you have a form capable browser. To run a scubasearch through the web, click here, which will lead you to http://scifi.squawk.com/cgi-bin/scubasearch-cgi.
If submitting your search by email, place the search pattern you want in your Subject: line. The search is CaSe InDePeNdEnT. Up to 10,000 result lines will be sent to you if you put in a general enough search pattern. As an example, to find articles which contain the string "dive watch", "diving watch" or close approximations, send mail to scubasearch with "Subject: div.*watc". "div.*wat" would not be good because that would get you "dive...water". Another bad search pattern is "cuba" because that will select every article, because cuba is part of scuba. Try "\<cuba\>" instead. Multiple level searches: Supposing you want to find a posting that mentions accidents in the Cayman islands. You could search for "accident.*Cayman|cayman.*accident", and that would tend to find some of them, but it wouldn't find postings where caymans was mentioned in the subject line (for example) and "accident" was mentioned somewhere in the body. To get around this, I've added a syntax that the shell script will use to run multiple grep passes. You just separate the arguments to the successive grep passes with an &. For our example above, you could code "Subject: cayman & accident". The shell script will run grep against all of the files with the argument "cayman" as he search string, and then run grep again with the search string "accident" against the files that result from the first pass. You can stack these to an arbitrary depth. You can also get as complex as you want using this feature. For example, you might want to do a search for articles that I didn't write with cayman in the subject. This pattern might do it:
Subject: ^Subject:.*cayman & -v ^From:.*njs-v can be specified on a second or subsequent grep pattern (after the &, as shown above) and eliminates all articles that contain the grep target. This is not a hook for general grep options. This is a special option that changes the action of the shell script.
You can limit your searching to a particular date range by specifying a line as follows:
Searchdates: [fromdate] [;todate]The format of the date is pretty liberal, and can include patterns such as "01 Jan 91" as well as "1 year ago". You can leave out the todate, or leave out the fromdate just by starting with a semicolon.
You can get further information about egrep patterns by sending mail to scubasearch with "Subject: help". There are more detailed instructions regarding the date and the inverse searching in the help file, as well.
You can get a copy of this FAQ by sending mail to scubasearch with "Subject: FAQ". You can do a search for someone else by naming them in a reply-to line, either in your mail header or the message body.
Advantages are that every posting is there. Disadvantages are that you will get random stuff which happens to mention your search string if it is not specific enough, and you might get tons of stuff you don't want. If you do make a successful scubasearch, consider editing the result and mailing it to Peter Yee for inclusion into the organized rec.scuba archives so that the next person has instant access to the information.
Note that due to a problem on the scifi system, the entire old article database was wiped out on 8/21/94. The accumulation will start again. Unforunately, it was just too big to back up with my limited resources.
Seriously consider doing a scubasearch or looking in the archives at ames before asking your question. If there hasn't been any conversation on your destination recently, then by all means ask.
Diveskins are typically made of Lycra or some other stretchy fabric. The warmth supplied is minimal. Typically, they are used to prevent stings from jellyfish, and to protect from accidental coral contact. Sport divers tend to wear skins in water warmer than 80F degrees, or under wetsuits, so that the wetsuit will slide on easier.
Next up in warmth is the Darlexx suit. This is a suit that is similar to a diveskin, but which is made out of a fabric that slows water flow. There have been reported problems with the Darlexx fabric "delaminating" or coming apart. An alternative is made by Aeroskin, and uses polypropylene and lycra. Depending on how warm blooded you are, you might be able to wear Darlexx comfortably down to 72F. A Darlexx suit is a wetsuit. It does not fit like a diveskin, and is not really a substitute for a skin.
Wet suits are made of neoprene rubber. The suits serve two purposes: They reduce water circulation over your skin, and the air impregnated neoprene insulates you from the cold water. At the worst, a poorly fitting wetsuit can ruin your dive by letting you get so cold that you get hypothermic, or by being so tight that it cuts off your circulation. If you are not well fitted by stock wet suits, you can have one custom made. Custom made wetsuits are not that much more expensive than stock ones, and fit much better. Wet suits come in several thicknesses and styles. People wear different styles of wet suits between 32F-85F. Most people find that temperatures below 45-50F are not comfortable for longer than a few minutes in a wetsuit.
Dry suits are used by prople between 70F-28F. (For extended commercial operations at near freezing temperatures, heated water is pumped through a special suit or underwear set.) (Temperatures below 40 require special environmental protection for regulators, controlled use of inflators, and (hopefully) redundant breathing systems.) You should consider getting special training before you wear a drysuit. Even fitting the drysuit is not quite as straightforward as fitting a wetsuit. A drysuit is useful at a wide range of temperatures because you can vary the amount of warmth by wearing different underwear with the suit.
The following discussion of drysuits is by email@example.com:
Drysuits fall into 4 main categories: foam neoprene suits, nylon or tri-laminate shell suits, vulcanized rubber suits, and crushed neoprene.
Foam Neoprene Suits:
These suits are very similar to wetsuits in they are made out of neoprene with the seams sealed. Even flooded, they will retain much of their insulating ability and buoyancy. At shallow depths, they are probably the warmest suits and will require the least amount of undergarment thermal protection. However, like wetsuits, at depth, the neoprene is compressed causing a reduction in both thermal protection as well as buoyancy. Also, they take a long time to dry, and can be very difficult to repair. Like neoprene wet suits, foam neoprene dry suits have a useful life of somewhere around 300 dives before the suit no longer retains sufficient thermal protection.
Nylon or Tri-laminate (Shell) Suits:
Shell suits are made out of various types of nylon. There is a wide range in the durability and resistance to abrasions of these suits. The advantages of these suits are that they are very light, easy to pack, dry very quickly, and are easy to don. They do not stretch so they must be large and baggy enough to allow freedom of movement. This can make them higher drag while swimming. They provide no thermal protection themselves, so appropriate undergarments must be worn. They are easy to repair in most cases.
Vulcanized Rubber Suits:
These suits have many of the same advantages and disadvantages as the nylon suits. They are relatively easy to don, they dry quickly, and repairs are easy. Depending on the thickness of the rubber will determine how durable the suits are and how resistant to abrasions. The most durables will be very expensive and the less expensive suits tend to need repairs often. The drag with vulcanized rubber suits tends to be high. These suits are often best for diving in contaminated water (with additional equipment and training of course).
Crushed Neoprene Suits:
These suits are neoprene suits which have been compressed. This means the suits themselves do not compress at depth so they do not lose buoyancy or insulation at various depths. The material is extremely durable and is very resistant to abrasions. The suits are somewhat heavier than nylon suits and take longer to dry (about 24 hours). Repairs can be more time-consuming because you must wait for the suit to be completely dry before doing the repair. The suits are very flexible, so they are easy to don and are meant to be form-fitting which reduces drag while swimming. They provide some thermal protection so you can generally wear less undergarments than with a shell or vulcanized suit. These suits tend to be the more expensive types of suits along with the heavy duty vulcanized rubber suits. Also, as of this year, crushed neoprene suits are available in women's sizes.
There are a number of other items to consider when purchasing a drysuit beyond the material of the suit itself.
Boots: Most drysuits today come with attached boots. This avoids the problem of additional seals at the ankles which also make your feet colder and another place to leak. Some suits have latex or other sock-like boots. With these drysuits, you wear wetsuit boots over for abrasion protection and additional thermal protection. Pros are you can generally wear the same size fins, if your boots wear out, wetsuit boots are much cheaper and easy to replace. Cons are they can be less warm than attached boots worn with thermal undergarments.
Wrist and neck seals: Seals primarily are either latex or neoprene. Latex is more flexible, is easy to don, but requires more care. Latex seals are less durable and need to be replaced at least every 2 years. However, latex seals are easy to repair and relatively easy to replace. Neoprene seals are more rugged, but most people find them harder to don and more uncomfortable to wear. Neoprene seals also tend to leak more than latex seals, but they are warmer than latex seals.
Other items to consider: Suspenders will be very useful to keep the crotch of the suit from sagging. They will be helpful while swimming or walking out of the water and are especially useful when you remove the top part of your dry suit. Since one of the most expensive parts of a suit to repair can be the waterproof zipper, a protection zipper is very useful. In the case of latex seals, a warm collar is a nice option as is an attached hood.
Yes, it is really possible. The rat was breathing liquid in the scene you saw in the movie. No, it is not done with people (except with premature babies to replace missing surfactants - this has been reported on Hard Copy a US TV tabloid news show, complete with pictures of the procedures and one of the surviving children). A widely cited study involved a single adult subject who had one lung filled with the liquid, but who had problems with pneumonia afterwards. It is considered highly risky. To pull an old thread on this from rec.scuba, do a scubasearch with the subject: ^subject:.*liquid scuba
The liquid is a chloroflourocarbon, like freon, but with a higher boiling point.
There are many, many magazines and journals. I've created a file called scubamag.txt, which I have placed in the archive at ames. This file, too long to place here, reviews many of the magazines which are around. At this point, many of the comments in this file are obsolete.
The safety of contacts revolves around several issues:
At least one study has indicated that there is an increased possibility of Acanthamoeba infection when swimming with contact lenses. Other practitioners, who do prescribe soft contacts for swimmers, claim that there is no proof that the contacts were the proximate cause of the infections, but give no arguments as to why they feel that there is no correlation.
Whatever you do, please avoid asking this question in rec.scuba. It is a very frequently asked question. Do a scubasearch on "contacts" or "prescription", and you will get many thousands of lines of opinion. People should follow up to this question by email if it is asked again [IMHO], unless they have new study information or something to quote that is substantive. (If it is substantive enough, I'll put it in as part of the FAQ answer.)
First off, carrying a redundant breathing system is a good idea. There are a couple of important questions.
Some British BCs have a small air bottle attached to the BC. With proper training and practice, it is possible to use this air for breathing. But since this isn't a straightforward regulator system, we won't discuss it here either.
The bailout bottle is available in sizes as small as 1.2 cu ft, and as large as 3 cu ft. The best known brand is "Spare Air". The bottle has a regulator that must (for older models) be switched on before use. Bailout bottles can cost between $200-$300. The ones sold at a discount by mail order houses are typically smaller bottles of older design.
The pony bottle is a smaller spare tank that is actually a small standard scuba bottle, and attaches to a standard regulator. Many people use an inexpensive regulator on their pony bottles. You also need some sort of mounting system. Pony bottles can cost between $250-$350 depending on the regulator selected, the size of the pony, and the care you take while shopping. You can get a 13 cubic foot pony (in 2000 PSI and 3000 PSI models), a 17 cubic foot pony, a 30 cubic foot pony, a 40 cubic foot pony, and some other sizes.
The independent twin tank is a second tank which is the same size as your first tank, and which has its own regulator. Since the two tanks fit into a single double tank bracket, they may look like a set of doubles, but, in fact, they are two separate tanks. The independent twin tank is a good option for certain specialty diving, like wreck penetrations or extreme deep diving, but I won't discuss it further here. Costs vary widely depending on how much the mounting costs, the type of tank, and so forth.
# Total consumption (ft^3) # Total consumption (ft^3) without 15_ft Safety Stop  # with 15_ft Safety Stop [1,2] # Consumption rate (ft^3/min) # Consumption rate (ft^3/min) Depth | 0.5 | 1.0 | 1.5 | 2.0 # 0.5 | 1.0 | 1.5 | 2.0 -----+------+-------+-------+-------#-------+-------+-------+------ 60 | 1.66 | 3.32 | 4.98 | 6.64 # 2.75 | 5.50 | 8.25 | 11.00 80 | 2.33 | 4.66 | 6.99 | 9.32 # 3.42 | 6.84 | 10.27 | 13.69 100 | 3.10 | 6.21 | 9.31 | 12.41 # 4.19 | 8.39 | 12.58 | 16.78 130 | 4.45 | 8.90 | 13.36 | 17.81 # 5.54 | 11.08 | 16.63 | 22.17 150 | 5.48 | 10.95 | 16.43 | 21.91 # 6.57 | 13.13 | 19.70 | 26.27 200 | 8.48 | 16.96 | 25.45 | 33.93 # 9.57 | 19.14 | 28.72 | 38.29 Notes:  Total consumption includes 30 seconds at indicated depth, and a 60_ft/min ascent rate.  Assuming a 1/2 consumption rate during a 15_ft safety stop for 3 minutes.The numbers beyond sport diving depths are here only for reference, and not to encourage you to dive those depths. Redundant air only reduces one of the dangers you would face in diving to those depths.
The largest Spare Air holds just under 3 cubic feet. The smallest available pony bottle holds 13 cubic feet. You can look at the chart, estimate your surface consumption rate, try to estimate what it would be in an emergency, and see where you fit in.
It is almost certain that if you were diving deep, you'd want more air than the chart shows, as you might need to make a longer decompression stop.
While some people have tested bailout bottle ascents from as deep as 100 fsw, it should be emphasized that these tests were not performed under stressful conditions. Typically, they are already neutrally buoyant, ready to ascend, and are consuming less air than they would in an emergency. Referring to the above chart, you can see that this would be possible for a diver who had a consumption rate of 1/2 cubic foot per minute, and who left immediately upon switching to their bailout bottle rather than taking time to get settled.
Opponents of bailout bottles believe that bailout bottles are useless diver decorations, mainly because the bailout bottles do not contain enough air for an emergency. They argue that from the time you switch to the bailout bottle, you have only enough air to ascend directly to the surface. You have no time to solve problems and little or no air to make yourself positively buoyant. A final argument is that a bailout bottle might actually give you a false sense of security, and make you less safe than you might be without one.
Perhaps the final judgment should be made using the above chart, and the depth to which you plan to dive. If $$/cubic foot is a consideration for you, then you would probably prefer a pony bottle to a bailout bottle. Many people do all of their diving between 15-40 feet, and never dive deeper than 60 feet. These people would probably find the largest bailout bottle useful. If you go deeper, or if you might go deeper someday, consider a pony bottle of the appropriate size.
There have been rare occasions (one reported, at the Hong Kong airport only) where people have been told that they simply can't bring their scuba bottles on their flight, valves on or off, and have had to abandon them at the airport. This would probably equally apply to bailout bottles and pony bottles. You should plan on draining your bottles of any type completely before flying to comply with airport regulations, and you may have to remove the valves to prove to the airline's satisfaction that the bottles are completely drained. It is a violation of US FAA regulations to transport a bottle on an airliner pressurized to more that 41 PSIA. Airlines may have more stringent regulations.
The Casio dive watches are supposedly rated in static pressure, not dynamic pressure. The act of swimming, moving your wrist, bumping the watch, using the controls, etc., causes large amounts of dynamic pressure, which can flood your watch.
Casio used to rate their watches by activity. 100M watches were rated for snorkeling, and only 200M watches were rated for scuba diving. 50M watches were for showering.
Net experience seems to indicate that your 50M watch is quite likely to flood if you use it for diving, your 100M watch is somewhat likely to flood, although some people have used 100M watches for diving successfully, and your 200M watch is probably not going to flood. A few people have used 50M watches for diving, but pushing the buttons at depth, accidentally or on purpose, may flood the watch.
Given that a Casio G-Shock is only about $50 at a discount store, and that a regular 200M Casio is likely to be around $40, many people seem to think that skimping further than that (since that is about the cost of a dive) is false economy, since, if your watch was your only timing device, you'd have to abort if it flooded.
There are people who believe that this means that some watches are rated in "marketing meters" and others are rated in "real meters". Regardless of that, 200M Casios seem to work for scuba and others are marginal.
If you are interested in information on the Citizen Hyper Aqualand, and you are not happy with the software you got with your watch, you might try the following URL: ftp://ftp.netcom.com/pub/ca/cader/scuba which contains information and utilities to dump the Citizen Hyper Aqualand.
Um, how long has it been since you have done any diving? And how much diving did you do when you were current? If it has been a long time, maybe you should consider taking a new certification course. Your old certification card may still be good, but equipment changes all of the time, diving practices and techniques change all of the time, and unless you've been keeping up, you may find yourself either at a loss, or not diving as safely as you might without current training.
Now, the first step in replacing your C-card to consult your instructor, or the dive shop you were taught through. They should have a copy of your records. If you can't contact them, calling the certification agency might well be your best bet. Here are some certification agency numbers.
Scuba Schools International (SSI) +1 (303) 482-0883 The Italian arm of SSI can be contacted through: http://www.tizeta.it/info/ssi/ SCUBA SCHOOLS INTERNATIONAL ITALIA Via Bergami 4 40133 BOLOGNA - ITALY tel. +39 51 383082 - fax +39 51 383554 E-MAIL firstname.lastname@example.org National Association of Underwater Instructors (NAUI) (800) 553-NAUI (USA) or +1 (714) 621-5801 NAUI Canada: Call NAUI in California. Email: email@example.com or firstname.lastname@example.org http://www.naui.org Handicapped Scuba Association (HSA) +1 (714) 498-6128 Professional Association of Diving Instructors (PADI) USA (714) 540-7234 http://www.padi.com National Young Men's Christian Association SCUBA Program (YMCA) (404) 662-5172 American Nitrox Divers Inc. (ANDI) (516) 546-2026 International Diving Educators Association (IDEA) (904)744-5554 National Association of Scuba Diving Schools (NASDS) The phone number for NASDS is 800 735-3483 [(800) 735-DIVE] 901 767-7265 Professional Diving Instructors Corp. (PDIC) (717) 342-9434, Fax (516) 546-6010 The address of CMAS is: Viale Tisiano 74 00196 Roma Italy tel. +39-636858480 fax. +39-636858490 "Contact by Phone is known to be Erratic"
It depends. If you're looking for a referral, try talking to your instructor, or to your dive shop. Alternatively, a dive travel agent might be able to help you get into a good place, and arrange your checkout dives for you as well. Finally, do a scubasearch for your area, and then maybe ask on rec.scuba.
Also, the certification agencies maintain referral lists. See the answer to question 12, and call them. They may be able to refer you to an instructor or a facility that can complete your referral.
Call your agency (see agency list above) and get the address to write to complain to them. The general rule is that they will investigate (especially if they get several complaints) only based on complaints in writing, and that they will not contact you to tell you the results of any action that they take. They will investigate one complaint, if it is really blatant.
There are two ways to get scuba related mail. Both involve the bitnet listserv system, and both are run from Brown University. The LISTSERV administrator there is Catherine Yang, but these things are designed to be administered automatically. The two lists are scuba-d, which holds the scuba digests that are constructed from the postings to rec.scuba, and scuba-l which is a completely independent scuba related discussion list. There are some scuba-d archives available at http://scifi.squawk.com/digests.
You never send subscribe or unsubscribe requests to the address of the list. In fact, if you do, they will be relayed to all of the people who get stuff from the list (and probably ignored). To sign onto or sign off from a listserv list, you send mail to userid LISTSERV. For example, to sign on to scuba-d so that you still get the rec.scuba postings, send mail to LISTSERV@BROWNVM.BROWN.EDU, with the text:
SUB scuba-d your name
You must replace the string 'your name' with your own name. To subscribe to scuba-l, send the same message, but replace scuba-d with scuba-l.
To find out more about how to use the listserv system, send mail to LISTSERV with a text line that says 'HELP'. For your convenience, the response to a HELP command is reproduced below.
If you don't have the ability to post news to rec.scuba locally, you can mail your postings to email@example.com. (This is not a general mail-to-news gateway, it works only for a few groups in which I have a personal interest.) This is how someone with e-mail only access could post to rec.scuba after reading the newsgroup via the scuba-d mailing list. To post to rec.scuba.equipment, mail your postings to firstname.lastname@example.org and to post to rec.scuba.locations, mail your postings to email@example.com.
The process that produces scuba-d purposely tries to delay postings until it gets a complete thread. In particular, it will use the References: fields and commonality of Subject: contents to try to build a time ordered thread. It selects threads to put into a particular digest by looking at the age of the oldest posting in a thread. When a thread is selected for output, the entire thread is output. Thus, postings may not come out in an order that seems 'logical', especially if people follow-up to unrelated postings. There is a logic to it, however. A side effect of this is that the headers come out in a different order than the postings do, in any particular digest. All postings do eventually come out of the other end of the pipe. Under normal circumstances, as many as four digests may be posted per day.
Revised LISTSERV version 1.7c -- most commonly used commands Info <topic|?> Get detailed information files List <Detail|Short|Global> Get a description of all lists SUBscribe listname <full_name> Subscribe to a list SIGNOFF listname Sign off from a list SIGNOFF * (NETWIDE - from all lists on all servers REView listname <options> Review a list STats listname <options> Review list statistics Query listname Query personal distribution options SET listname options Set personal distribution options INDex <filelist_name> Obtain a list of LISTSERV files GET filename filetype Obtain a file from LISTSERV REGister full_name|OFF Tell LISTSERV about your name There are more commands (AFD, FUI, PW, etc). Send an INFO REFCARD for a complete reference card, or INFO ? for a list of available documentation files. Postmasters are: Peter DiCamillo / ListMaint <CMSMAINT@BROWNVM>
Jonathan: firstname.lastname@example.org says:
I am hosting a diving software archive here at halcyon - if you want to put me in the FAQ as a site for scuba related software, feel free to do so. Its small now, but I am building it as I find more stuff. as of now, it is only PC based stuff, but I am looking for Mac/Unix/Amiga as well. contact me for more information if you need it.
It can be reached through the web at :
(changed on 18 July 1996:)
Also, the NOAA web site address is:
E-mail contact is email@example.com
Here are more interesting scuba URLs:
Kevin Grover, grover@CS.UNLV.EDU, tells me:
About the blurb on dive computers. The information is no longer preliminary. It is now in version 2.0 and is called "Internet Dive Computer Review" (IDCR for short).
Also, it is a multipart HTML document with a main file of:
If you could update the rec.scuba FAQ it would be great. (BTW the above document also includes addresses, phone numbers, fax numbers, email/ftp/www addresses for manufacturers).
(Currently there is no FTP file, I'm working on putting something together though).
There are actually several methods of clearing regulators. It almost seems that regulators want to be clear. The two that most folks are taught are exhaling and pushing the purge button. You can also seal around the reg mouthpiece with your lips and either use your tongue as a piston, or use a chewing motion. As your mouth volume decreases, water will be forced out through the reg exhaust, and as your mouth volume increases, air will be drawn in through the demand valve. In 3-5 quick cycles, your reg will be clear.
This is handy if you've exhaled all of the way, and your hands are full, such as when you are doing a buddy breathing exercise. Try it sometimes, preferably in shallow water the first time.
Scuba diving is a physically demanding sport, which requires a healthy heart, well able to tolerate exercise, and healthy lungs. Additionally, any illness which might incapacitate you, such as with a siezure, or with unconsciousness, such as uncontrolled fainting. There are many medical conditions which are considered disqualifying for scuba diving. The Diver's Alert Network (phone +1.919.684.2948) will provide over-the-phone advice about medicine, medications, diving, and their interaction, as well as assisting you in finding the appropriate chamber or a local doctor who is familiar with diving medicine and so forth, and is a worthwhile organization to join.
Some medical conditions which are generally considered disqualifying (although there are exceptions for well controlled conditions, in some cases, consult your doctor) are asthma, diabetes, epilepsy or any other siezure disorder, history of spontaneous (or, from some sources, any) pneumothorax, emphesema, heart illness which inhibits your ability to exercise to a certain level, and others.
There is some experimental evidence that diving while pregnant could be dangerous for the fetus, so it is contraindicated. This is a compressed air issue, so shallow, reasonable snorkeling should be fine, if your doctor says you can tolerate exercise and swimming.
I have a great scuba related GIF/piece of software/sound sample. What should I do with it?
Please bear with me for a second. By convention, the net is divided into areas. There is an area for written discussion, an area for posting gifs, an area for posting binaries, and an area for posting sound samples. The total volume of postings in the net is very high. It is so high that many sites are picking and choosing the posting areas (rec, alt.binaries, etc.) that they want very carefully. One area that many sites have cut is binary postings. Many news administrators consider binary postings to be marginally useful, in comparison to their size. So they don't carry them.
I suspect that many news administrators also consider rec.scuba to be of marginal utility. If rec.scuba becomes loaded with binaries, it will be considered a binary group, and will be dropped by those sites.
Finally, many folks pay by the byte for their connections. If they get rec.scuba, they have signed up for discussion, not for binaries. Please respect their wishes.
If you have a binary you wish to make available, contact Peter Yee or Jonathan <firstname.lastname@example.org> and let them know. If you want to post it, post it to the right alt.sources or alt.binaries group, and post a reference to it here in rec.scuba.
Well, there are many things you can do. You can contact your news administrator, who should know what to do about contacting your upstream sites. If you are on a pay service, contact your help desk. What you should *not* do is cluelessly post a test to rec.scuba. This is incredibly rude, as well as useless. What will probably happen with your test is that whatever is holding up your newsfeed will hold up your test posting, and no one will see it until the logjam is broken. Then it will be distributed, at just about the same time you start seeing postings again. Alternatively, it will be distributed immediately, because the blockage is one way, and people will respond to it, but it will all be useless, because you won't have seen the responses. You will be wasting your time, and everyone else's, as well as network bandwidth.
Occasionally, a news administrator will have a specific problem with propagation of rec.scuba, and will have to post a test. Those postings are few and far between. If they ask for a response, respond via email. Generally, news administrators can use a group such as misc.test for testing.
The above also applies to scuba-l. It is clueless, rude, and a waste of time for the average individual user to post tests in public newsgroups or mailing lists, and it is equally clueless, although less rude, to respond to them in public newsgroups. Contact the your news administrator if you think you are having trouble with news. Contact your postmaster if you think you are having trouble with email. Contact the mailing list maintainer if you think you are having trouble with a mailing list (typically at the listname-request address, or, for scuba-l and scuba-d, at email@example.com, for automated help).
It is a good idea to restrain yourself and not respond to these postings in public. In fact, it is a good idea not to respond at all. There are automatic responders listening to misc.test, just waiting to eagerly and automatically respond to your posting.
This is called "spamming". More and more frequently, these days, people are putting this sort of stuff on the net in the hopes of making some money. Generally, the best thing to do is ignore it. However, if you feel that you must take some action, then mail to their postmaster. Include the entire message, including all of the headers, such as path, etc., to allow the postmaster to more accurately determine if it originated at their site, or was forged. Do be careful in your wording, however: Some of these postings are forged in the hope of causing a site to be flooded with hate mail.
For my site, scifi.squawk.com, my postmaster address would be firstname.lastname@example.org (me) or email@example.com.
GPS stands for Global Positioning System. It is a system that was launched by the US Government to use in military applications. Additionally, For more information, see http://www.utexas.edu/depts/grg/gcraft/notes/gps/gps.html, or do a yahoo search on the word GPS.
An ordinary hand held GPS, with a directly attached antenna, will not work under water. The frequencies and signal strength of GPS are such that they will not penetrate more than a very thin layer of water.
GPS accuracy is usually only a couple of hundred feet. It is affected by a number of factors including intentional fuzzing of the signals used by civilian units called Selective Availability or SA (since precise positioning is considered to be information that has military value), variations in the speed of light as signals pass through the atmosphere, and other similar sorts of things.
There are a couple of useful things that you can do with GPS regarding diving:
An EPIRB is an emergency radio beacon used in lifeboats and by downed airplanes to attract attention. They are used by divers who are worried that they might lose their boat because of current, or because of drift diving. Commercial divers who work in high current use them.
Marine EPIRBs are designed to be used on lifeboats. They must resist immersion, and splashes, and must work when wet. Generally, they do not have to resist deep immersion.
Transmission of an EPIRB signal is equivalent to the transmission of an SOS. The EPIRB signal will not be received if the antenna is immersed. If the Minnow had an EPIRB, Gilligan would have been rescued. :-) (US TV Joke.)
The most apparently waterproof is the Litton Micro B. It fits into a BC pocket with the antenna folded over, and is hermetically sealed. The batteries must be replaced by the factory, after seven years. It is rated to 30 feet by the factory, but like the 50 meter watches, mine still works properly after deep immersion, and uses a magnetic through-the-case switch, so keep it away from magnets. It is positively buoyant (it floats).
Every year, some divers are lost during lobster season here in Palm Beach county. They get blown away from their boats by current, or they separate from the other groups in their drift and the boats lose sight of their flag, and they don't get picked up, sometimes for days, if at all. A working EPIRB would get the Coast Guard on the scene, even if they couldn't be reported.
It should be pointed out that your EPIRB requires an FCC license in the US and the license you already might own may have to be amended to include the EPIRB if you don't already have one. A single ground station and a satellite can triangulate your transmission to within 10 miles.
If you are not in the US, you should check with your local coastal marine authorities to see what licensing is required and if the local authorities will respond to the signal.
There has long been great controversy over commercial postings on Usenet and in the scuba-l mailing list. Commercial postings clearly generate more heat than light. Some people clearly appreciate commercial postings, while other folks are completely alieniated by them. Since the purpose of a FAQ is to reduce the heat in the newsgroup, I feel that I should present a compromise that I feel that most people are willing to live with, without generating heat.
Generally, I think that the following is considered reasonable:
On the other hand, if you avoid irritating people, they will want to do business with you. That is what you want, and I believe that the redustion in the total heat will be what the folks in rec.scuba and scuba-l want.
Finally, consider posting your announcement to the scuba-commerce mailing list. You'll find an audience that has signed up to see your commercial announcement, on a list where chit-chat is frowned upon. See the scuba commerce web page for instructions on how to subscribe, or mail to firstname.lastname@example.org to subscribe and for posting instructions. This is a closed list. You must be subscribed before you can post.