Estimating Weight Needed for New BCD

[Mayor]

Your going about this totaly wrong. Nothing can replace a weight check. Get all your gear and head off to a local pool. Take one full tank and one that's 500 psi. Strap on the 500psi tank and add weight as needed so you can hold a 5 foot stop. As gear and wet suits change your going to have adjust. Also as you become more relaxed in the water more weight will be removed. Then burn off the full tank just working on your control in the water. Paying a GOOD instructor for a few hours would also be a Huge help getting fine tuned. For salt water you can add a few pounds but again a weight check just off the beach would go along way to improving you experience. Guessing or estimating will only make you over weighted and IMHO is just as bad as not having enough weight.Wish someone told me this when i was OW diver.

 

[MaverickNH]

I committed to the KnightHawk BCD already, so too late for a wing for now, and I'll be doing shore diving for my coldwater exploits. But I get the point about being able to control weight drops while wearing that buoyant 7/8mm coldwater wetsuit. I have 2x5lb & 2x3lb lead for my weightbelt already, and so can distribute between a belt and BCD for coldwater dives and go back to just integrated BDC weight for the infrequent trips to warmwaters.

Reasonable?

 

[MaverickNH]

Mayor - that I can do. While my LDS's pool is iced over, they have a course at the YMCA pool 8Jan and I'll get in the deep end then to adjust weights. Thank for the suggestion.

 

[RonFrank]

You will need at Least 2 more 5# weights and likely double what you own. Weight has a way of disappearing so a couple extra bricks is not a bad idea. I'm guessing between 25-32lbs. Semi dry suits are buoyant. If you wear a 5mm hood that's good for a few lbs as well. Rent a bunch and figure out what you need.

Try and do your pool weight check with an empty tank (500lbs). Also try and soak your wetsuit. Get to the point where you can barely sink, now take a deep breath and exhale and hold. You should sink to the bottom. If not add more weight. When I say hold I don't mean close you airway, leave the airway open, but don't inhale. Never close your airway when diving. This is fresh water so add 6lbs for salt. If you can not do the weight check with an empty tank than add another 6lbs to make up for the full tank.

To recap full tank add 4-6lbs, Salt water add 6lbs or a total of 10-12lbs just for an AL tank and salt water. If you dive something other than an AL80 ask the LDS what the empty buoyancy is and adjust. Keep in mind its always best to be a couple lbs heavy vs under-weighted. If you are under-weighted you can not stay down and rocketing to the surface is a very bad thing, Very bad.

Good Luck.

 

[MaverickNH]

OK - I got in the pool with my 7/8mm hooded fullsuit, booties, gloves, etc., a 3000psi AL80 tank, and adjusted to 24lb. Floating at eye-level with full breath and descending to bottom on full exhale. I tried to burn a tank down to 500psi during the time I had, but didn't get below 2000psi. So I'll have to go by the seat-of-the-pants +6lb and go in fw at 30lb and sw at 36lb. Sound right for now?

 

[RonFrank]

Sounds good. Recognize if you want less air in a tank just open the valve and bleed some off. You can also ask someone if the is an empty tank you could use for a weight check. But adding 6lbs is close enough for Gov work.

 

[fisheater]

When I set up a new tropical BP/W system and was doing a pool check at the LDS, I asked them to leave a used AL80 out from their next class.

That way, I only had about 1000 psi to start and could work on getting my weighting down before just a bit of purging to 500 psi.

 

[MaverickNH]

Thanks y'all - I'll get that 500psi tank next time for sure.

BTW, when using my back-inflation BC, is there any guideline I might consider for distributing that weight by %age between non-ditcahble BC trim pockets, ditchable BC pockets and weight belt when kitted out with full cold-water gear vs 3mm temperate/tropical gear? I think I'm seeing above that for 30lb cold water weighting, the suggestion of 6 in trim pockets and 6 on belt, or 20% non-ditchable BC trim pockets, 20% belt, 40% ditchable BC pockets. Does that recommendation change between cold-water and tropical/temperate water gear?

 

[txapacheguy]

I am not going to try to offer advice on weight distribution for an integrated BCD because I do not dive one anymore, but I will tell you how I approached the problem myself with a backplate/wing setup. When I still dove single tanks, I had a 6lb back plate, 10 pounds divided between two pouches on the waist belt of my harness, 6 pounds divided between two pouches on my tank band, and when I dove my drysuit, I kept another ten pounds or so on a weight belt. This allowed my rig (with a 30lb wing) to float itself without me in it, and kept me from having a murderously heavy weight belt(I do not like weight belts). If I were to go diving with my Zeagle Ranger and drysuit right now, I would probably do everything about the same, but put a little extra weight in each side pocket because of the lack of a 6lb backplate.

If you have not purchased all your weights yet, try to take a look around on the local craigslist ads or classifieds. Normally, people who have old obsolete scuba gear for sale with have a belt with some weight on it laying around. I have yet to pay more than one dollar per pound for lead weights, and I have over a hundred pounds of them at my house.