Weight check at start of a dive??

[dumpsterDiver]

Read the description carefully... the direction was NOT to exhale and see if you sink... It was, exhale "slightly" and see if you sink.

I will let someone else look up what volume of air will be expelled when a diver fully exhales (versus) slightly..(a couple of pounds worth, i'm sure). As mentioned above, it should work ok, plus I think most of us are assuming that divrs who need this kind of "hand holding" are most likely diving in warm water with a single 80 cu-ft aluminum tank...

If you are diving with a dry suit and double 120's.. I sure hope you can figure out how much lead you need without too much supervision.

 

[TSandM]

It is not the end of the world to be overweighted during a dive- an extra kg or 2 doesn't require you to plow through a divesite. I regularly dive up to 4kg overweighted on the job and can still hover horizontally even in the clearly inferior Jacket BCD

I think tolerance for overweighting comes with experience in buoyancy control. After all, technical divers can go into the water "overweighted" by 20 lbs or so, and they cope. But for beginners, any extra gas in the BC is just that much more to get ahead of them, if they aren't completely on top of their buoyancy. But I will admit that I'd rather see a new diver a couple of pounds overweighted, than unable to hold a stop at the end of the dive.

 

[supergaijin]

I think tolerance for overweighting comes with experience in buoyancy control. After all, technical divers can go into the water "overweighted" by 20 lbs or so, and they cope. But for beginners, any extra gas in the BC is just that much more to get ahead of them, if they aren't completely on top of their buoyancy. But I will admit that I'd rather see a new diver a couple of pounds overweighted, than unable to hold a stop at the end of the dive.

(BOLD is mine)

The beginner cold-water diver faces "that much more" every dive due to suit compression. Experiencing cooler waters is an excellent way of learning how little one needs to use the BCD in the tropics.

It is rare for me to see a truly underweighted diver underwater- actually getting themselves down is usually beyond their abilities. Occasionally I do see divers who are unable to control their SS, but then are able to descend from the surface when I 'coach' them down.

 

[DivemasterDennis]

Not all day boat excursions offer the opportunity for the optimal weight chech: one done with a mostly depleted tank and saturated wet suit, if a wet suit is being worn. What was done here is common and crude, and often all that is available. That is part of the reason that we keep as part of our log book notes the exposure gear worn including # of dives on the wet suit (they get less buoyant with age ) and weight worn and body weight at the time of the dive. ( From time to time I become more buoyant with the addition of buoyant body fat, and sometime less buoyant through shedding of same). I keep a chart in front of our log books for each of us. This is an area where individual diver responsibility is key. If you are an inexperienced or infrequent diver, accept the assistance the local DM's will offer in weighting you. Remember, the key is to be neutral at the end of the dive, able to hold hover at a safety stop depth.
DivemasterDennis

 

[TMHeimer]

Agree with all said. I have 3 wetsuits. Did weight checks when I started out diving with each one. Followed the instructions and added weight to compensate for tank air used. Haven't done another check in my 7 years diving, though you're supposed to now and again (in case your body weight changes and of course if their are equipment changes). Never had any problems--ei. with safety stops, etc.

 

[Blastman4444]

My wife and I are new divers when we were in Key Largo the DM under weighted my wife stating that she doesn't need more then 12lbs. We used 14lbs when we got certified that was in a lake so the ocean could require more. I notice also you get funny looks if you use more then 10-12lbs like it's an expression of your abilities to control buoyancy and requiring less weight. We were diving at key largo in 30-40 feet she just kept floating up she got frustrated and went back to the boat. I ended up diving with the DM we were the only ones on the boat that day they took us out anyway.

 

[spectrum]

Not all day boat excursions offer the opportunity for the optimal weight chech: one done with a mostly depleted tank and saturated wet suit, if a wet suit is being worn. What was done here is common and crude, and often all that is available. That is part of the reason that we keep as part of our log book notes the exposure gear worn including # of dives on the wet suit (they get less buoyant with age ) and weight worn and body weight at the time of the dive. ( From time to time I become more buoyant with the addition of buoyant body fat, and sometime less buoyant through shedding of same). I keep a chart in front of our log books for each of us. This is an area where individual diver responsibility is key. If you are an inexperienced or infrequent diver, accept the assistance the local DM's will offer in weighting you. Remember, the key is to be neutral at the end of the dive, able to hold hover at a safety stop depth.
DivemasterDennis

Dennis I agree with you for the most part and you do raise a pet peve of mine.

My diving is almost exclusively shore diving but I've been on boats enough to understand the difficulty in futzing around with any sort of weight check. What chaps me is hearing divers saying that they can't dive right or enough because of the logistics and costs of boat dives. Most (I realize not all) dive destinations home and away offer some form of shore diving where a buddy pair can take a measure of time to sort tings out. Not every dive needs to be on a spectacular boat destinataion and as a mater of fact many shore dives can very memorable.

I too have a lot of gear data and with a few good weight checks I can adjust with puts and takes to splash with a workable anount of weight. Evety log enrty includes the full configuration and any issues or confirmation that it was spot on. Diving locally from trunks to dry in fresh and salt with a varity of cylinders this capbility is essential.

If a diver knows what they need they must understand the need well enough to stand up to DMs that think they know better. If a diver shows up clueless then lotsa luck and you may get what ytou deserve. Job 1 is understanding your configuration.

If this is individual responsibility why are you maintaining everyone's chart. Did I read that right?

Pete