Posted by Karl S. on January 27, 2003 at 20:47:00:
In Reply to: Deeper Diving posted by Tribes on January 27, 2003 at 10:41:47:
Scripps Canyon? Just off LaJolla about 250 yds offshore?
Driving to LaJolla to do some deeper dives than you can otherwise do around L.A. is probably good exercise.
I agree, that the way most divers in California are now trained to dive, by all of the agencies [PADI, NAUI, SSI, YMCA, IANTD, ANDI ...] it seems to me that any diving deeper than 60 fsw is "deep." This is about where the buoyancy problems begin, since the wetsuits get squeezed and the weight belts therefore rely completely on the B/C to buoy them up, and if a B/C is inadequate at this depth for the amount of lead the diver is wearing, then this is where overweighting problems begin.
So I would classify "overweighting" and "inadequate B/Cs" as the first problem as depths get deeper.
Zeagle makes great B/Cs with larger than usual lift capacity in their back-mounted wings. Mares and ScubaPro does too, but you just have to be careful that the lift rating on your B/C equals or exceeds 45 lbs for cold water diving. A lot of the cheaper B/Cs do not have adequate lift for cold water diving in wetsuits.
I agree with the notion that diving any deeper than this should start with basic deep-water training, and then perhaps culminate in staged decompression training and extended range diving.
Purging CO2 before submerging by relaxing on the surface, like a freediver does, is one way to reduce the nacosis effect at depth. Most people dont know or teach this, especially since almost everyone is in a hurry to gear up, jump in, then kick over to the anchor line or out away from the beach before beginning an immediate ascent. Narcosis is not the only hazard awaiting at depth.
Strong currents at depth, particularly at the sea mounts, may be the biggest hazard of all, as far as things that have killed divers. Even the biggest B/C sold may not save you against a strong current pulling you deeper. Sometimes it just depends on knowing the dive site, or going with a good guide or leader.