I heard at some cold regions, people use drysuit while learning OW, both thick wetsuit and drysuit can cause buoyancy problem, and cold is the root of all.Getting back to the person involved who started this thread ( @Mosizely ), your instructor is not “professional” in his way of dealing with your overweight problem. There are two things to consider here.
First, with a dry suit, you are actually trying to do two courses at once. One is the basic certification in scuba, and one is in the use of a dry suit. Dry suit diving is usually a specialty course, requiring you to already be certified in scuba. Dry suits add an additional buoyancy factor, that many are not prepared for dealing with. So think about getting your certification dives in a wetsuit first, then going to a dry suit.
Now, about the CESA, it is a “controlled, emergency swimming ascent,” as mentioned by CuzzA above. This ascent cannot be “controlled” if the diver is either underweighted or overweighted. As mentioned, the diver needs to be neutrally buoyant at the surface (deep breath, eyes out of the water when still, vertical). If the diver cannot remain still (no finning) and stay on the surface, that diver is not neutrally buoyant. A BCD is a “buoyancy control device,” and is intended to simply use added air to counteract the effects of a wetsuit’s compression. In freshwater, that can be 16-18 pounds of buoyancy lost.
I have years ago, when I was writing about buoyancy compensation issues for NAUI, simply taken off my weight belt at about 30 feet, tied a butterfly knot (a mid-rope loop) in the anchor line, and left my weight belt there. I then swam around completely neutrally buoyant in Clear Lake, Oregon (4000 feet altitude, freshwater) in a full wetsuit. When I was ready to surface, I simply swam over to the boat’s anchor line, retrieved my weight belt, put it on around my waist, and untied the butterfly knot (it’s easy to tie and untie), then swam to the surface. This was before BCDs were even available.
Now, about dry suits; they really do not need a BCD in order to work. For years and years, dry suits were dived without any BCD, as you added air into the suit to counteract the effects of pressure on the suit’s buoyancy (if it had any). Take a look at old Cousteau films in very cold water with the UniSuit. Many dry suits don’t compress like a wetsuit, and so there is no inherent loss buoyancy as the diver descends. BCDs are now routinely added as an additional “safety measure” which also conveniently increases the profits of the local dive shop (LDS). A BCD with a dry suit adds another dimension to the dive, more equipment, and additional low pressure inflators. This has led to fatalities (see a discussion of an Arctic dive off the U.S.S. Healy) when not enough LP inflator hoses were available for the octopus, BCD and dry suit.
Coast Guard Cutter Healy Deaths
http://navytimes.com/news/2007/01/ndeadlydiveweb070112/ They violated some very fundamental Navy Diving procedures. It sounds like they were just very excited and anxious to get in the water. They mislead their superiors and bypassed some of the more tedious and time consuming safety...scubaboard.com
Concerning your instructor, he appears more concerned about his own schedule and earnings than your safety. Switch instructors!
SeaRat
So not only switch the instructor, but also choose a warm ocean to learning dive is a good idea.
I hate quarry diving. Cold, poor vis and boring , I will never dive quarry unless chinese gov lock border again.
