Thank you for your response. I appreciate all of them.
Ken, DumpsterDiver, ZKY, Steve_Dives, and Shurite7, I guess, I need to give you a backgrounder of my physiology. I am 6-ft. 2" tall and weigh in at around 195-lbs. I do try to reduce my weight but at 36-lbs., I have trouble sinking and usually end up doing an uncontrolled ascent starting from 20-ft. while on safety stop. I have already emptied all air from my BC at this point. So, knowing my height and weight, do you still think I am over weighed?
No, I have not done any bouyancy checks because I never really had a good attentive buddy to begin with. I will need to keep looking for someone to dive with me and help me with bouyancy checks. I do know that I need to do a bouyancy check but I have been working down from 40-lbs. which was the weight they gave me when I did my O/W course. I did complain to my instructor at one time after I finished the course and she told me that they gave me 40-lbs. so I would stay at the bottom.
Using a Steel tank is a good idea to offset the bouyancy of a nearly empty Al.
Anyway, I will take all your bouyancy check tips and apply them when I do my next dive. ZKY, Steve_Dives, I will make sure I follow your Bouyancy Check tips. These are things that you only learn through experience. I have not read or heard of the 15-foot zero bouyancy thing but it does make perfect sense to make sure that you are neutrally bouyant at that depth at the end of a dive.
When I am diving in the tropics, I wear a 3mm full and 10 to 12-lbs of lead. My bouyancy is no problem. On a very recent trip to Cozumel, our DM told me after a couple of dives that my bouyancy is good enough to do Barracuda Reef (for very advanced divers only...high speed drift) as well as Devil's Throat and Maracaibo Deep. I did Maracaibo Deep and did well.
I dive a 2 piece 7mm wetsuit (7mm farmer john, and 7mm jacket, with 7mm hood and boots, and 5mm gloves), but I use FAR less lead than you, around 26lbs, and since changing my BC, I think I am going to drop a little more lead.
yes, there will be bouyancy swings as you go deeper due to compression of the suit. I do add some air as I descend, but I never come anywhere near the max of my BC (old one was about 35 lbs lift).
I think you need to work on the bouyancy and find out why you need so much lead. Then, maybe you can eventually drop some of it.
Ken
I think the larger capacity BC will be helpful, but I also suspect that you are diving with a little more lead than you need.
Your ultimate weighting goal should be that when you are done with a full length dive and hanging at 15 feet with 400-500 psi in your tank, all of your balast systems should be completely empty, that means BC (and drysuit if you're wearing one), and you should be able to regulate your stop with your inhaling and exhaling alone.
If you get this dialed in then your weighting is perfect. After you achieve this protocol: If you are light at the surface and have to kick head down to get submerged than so be it. If you have to pump quite a bit of air into your BC at depth then it is what it is, but ultimately at 10-15 feet with an almost empty tank you should be neutral with the bc completely empty.
I dive with a custom rubatex 1/2" commercial urchin suit (that's 12.5 mm - 25 mm on my chest!)
I also use:
Steel 100 - 3442 E7
A stainless freedom plate - 4 lbs
Oxycheq #30 signature wing on the plate
38 Lb weight belt
No ankle weights
Heavy black Scubapro jet fins
I am 100% neutral at 10 feet with an empty tank.
I can hold 15 feet if I keep my lungs on the full side, or just a quick shot of air into the wing and it's perfect.
Past 3 or 4 atmospheres of pressure suits don't change much with compression. At the first and second atmospheres they change quite a bit because the pressure difference is much greater.
I can use my #30 pound lift wing no problem down to as deep as I need to go (past 100 feet).
Some people tell me "Well, in case you need to pull something heavy up it's nice to have the extra lift".
I say that's malarky, if you need to pull something up that heavy then you need to use a lift bag not your BC.
Sounds like a lot of lead. Have you done any buoyancy checks, either at the surface or submerged? My favorite way to check buoyancy is to find a platform at 10-20 feet, deflate the BC so I'm resting on the platform (yeah, poor form, I know), and then slowly and carefully remove small amounts of lead until I start to rise. I will generally remove a couple pounds, inhale, see if I float, exhale, drop a couple pounds if I didn't float, and repeat.
Try using a steel cylinder which will help displace your weight. You may also be able to drop some weight.
Also, keep in mind the wetsuit looses it's buoyancy characteristics the deeper you go (the neoprene compresses). As you ascend the wetsuit becomes more buoyant and your AL cylinder also becomes buoyant.
I must admit, your dilemna is the opposite of what most people have. Most have a problem with buoyancy in shallower waters.
C
