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Hi, I didn't see the original message but clipped the following from Jeff Swanns email to the list. >At 08:09 3/11/00 GMT, Ee Michael wrote: >>I dive mainly in the tropics where a 3mm wetsuit is needed at the >>maximum.(no technical stuff whatso ever yet : just want to get all my basics >>in DIR correct first b4 any future advancements.) >> >>However , with a wetsuit , the max amount of weight needed for me to >>maintain a safety stop is about 5-6 pounds lead. >> >>So far i've already have decided on getting a backplate from halocyn and >>have my own custom made single tank adaptor ( about 2 pounds weight)and a 2 >>pound keel weight. >> >>was thinkning of either a ss or al hardcoated plate, however this means that >>my total weight would be >> >>1) keel weight (2lbs) + al harcoated plate ( 2lbs) + single tank adaptor >>(2lbs) which implies i do not need any more wieghts , which means i do not >>have any ditchible weights. >> >>2) keel weight (2lbs) + ss plate( 6lbs) + single tank adaptor (2lbs) which >>implies i do not need any more wieghts ( might even be overweighted ), which >>means i do not have any ditchible weights as well. >> >>so i guess a ss plate is out of the option. >>from what i have gathered in the past 6 months,i understand that when dive >>wet ,we use al tanks and MUST be able to swim out in the case of a bladder >>failure. >> >>no ditchible weights in both cases, what in the world do i do ? >>any advise/info greatly apprciated. I am in a similar situation, diving wet with warm water suits. I use an aluminium backplate and tank with 3 pound keel weight in winter (mid summer I can do without the keel weight). I don't really see any problem with this as my change in buoyancy is small and I'm confident I can easily swim up my rig if the need arose (on shallow dives I actually need to add a little more weight to be comfortable just hanging around, usually these shallow dives are night dives so the added weight is my canister light). The following is a rather long winded replied I made to a question on my non-use of a weight belt to SCUBA-L. Also check out my gear page if you like, shows how I've set things up... http://www.scu.edu.au/staff_pages/shartley/projects/gear/ ....BTW, have made a couple of changes recently on advice from the list and will be replacing some images soon, and adding some shots and video of me underwater. The following is a preview, a nice little MPEG that shows how streamlined and neat the setup is (many thanks to Tim Hochgrebe at Planula divers retreat http://www.planula.com.au/index.html for the MPEG)... http://wwwdev.scu.edu.au/staff_pages/shartley/projects/gear/simon.mpg >At 02:31 6/10/2000 -0400, you wrote: >>One last thing...Simon, as I saw it, you don't appear to wear any >>weights other than your tank weight, which is not ditchable. Is that >>Doing it Right? :-) > >From what I've read from various discussions, the DIR approach on weight belts (ditchable weight) is necessary when diving wet, not so when diving dry. Some folks use weight belts with dry suits in open water, some don't, the important thing is diving a balanced rig (drysuits give you redundant buoyancy and often the risk of an uncontroled ascent (loss of weight belt) is considered unacceptable so the weight belt is either not used or worn under the crotch strap). Wetsuits offer no redundant buoyancy in the event of a wing failure and there is a great shift in buoyancy during the dive due to compression of thick wet suits with depth and the need to carry extra weight to compensate for lighter tanks at the end of the dive. Meaning your heavy to start with and light at the end of the dive. > >My personal rational for not using a weight belt though is as follows (and I'm not pushing this as the way to go for others, I always recommend folks have ditchable weight (I'd use a light belt (I've mentioned in other posts up to 6 pounds) if I was diving with a thicker suit and had a greater buoyancy shift during my dives))... > >1) I have minimal shift in buoyancy during a dive. Locally I dive a shorty year round and use a small aluminium cylinder. I can actually free dive relatively easily with my wetsuit and no lead. I don't put much air in the wing at depth and have no air in the wing in shallow water, relying on breathing to regulate buoyancy. With limited shift in buoyancy I am never very negative even with no air in my wing (ie. could easily swim my rig up if the need arose). I should also point out that on ascending from depth any air in my wing (if intact) would expand, assisting my ascent (starting from neutral, I would soon be positively buoyant). > >BTW, on shallow dives (like my regular night dives off the shore) I am a little floaty. On these dives I carry a canister light (ditchable weight), so I'm comfortably neutrally buoyant (with little or no air in my wing). Shallow day dives I stick a small weight in the front of my wetsuit (again, easily ditched). > >2) I prefer to use what little lead I carry (3 pounds) for airway protection and surface stability. Tank weight is effective in maintaining a stable face up position on the surface and for good trim in the water. In summer I use an even thinner suit and don't carry any lead at all (I use a light weight aluminium backplate and single tank adapter). > >3) I use good quality/reliable equipment. I make a point of buying top quality equipment (have had plenty of help from the web) and putting thought into configuring it properly to solve any problems on the surface (avoid catastrophic gear failures in the water). Things like using DIN rather than yoke valves, Halcyon wings (well made, without dump valves all over them like most rec BC's (and other potential failure points), etc), reliable/simple regulators, fin straps that won't break during a dive, etc. > >4) I try to use good dive technique, plan dives well and maintain good buddy contact. Working as a DM I usually have a small group of divers to lead. I keep good close contact with my group pointing things out and monitoring air, etc. I therefore have several "redundant" air supplies close by. I plan dives so we go deep first then make our way shallower (surfacing away from currents and swell with good reserve). > >5) It's convenient and comfortable not having a belt. As a DM I have to gear up quickly, usually in the water. At present I only have to don mask, fins and kit, which I can do quickly and on the run. > >Well, I hope that answers your question. As I said I'm certainly not suggesting others do without ditchable weight. > >Cheers, Cheers, Simon Simon L Hartley RSM Website Coordinator\First Year Course Coordinator Associate Lecturer School of Resource Science and Management Southern Cross University P.O. Box 157 Lismore NSW, Australia 2480 Ph: (02) 66203251 or (61 66) 203 251 Fax:(02) 66212669 E-mail: shartley@sc*.ed*.au* http://www.scu.edu.au/staff_pages/shartley/index.html http://www.scu.edu.au/schools/rsm/ -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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