Wearing BCD on the surface.

[timz]

Hi everyone, I was on a diving day trip yesterday. One my first dive, There were 10 ppl including thr boatman on an extremely small boat.

When someone did a backroll on either side, the whole boat rocks severely. So, some divers throw in their BCD to the ocean and wear it on the surface. All that does that use BCD with integrated weight.

Initially, i decided to do the same. But I was afraid that I'll sink when i jump into the water because I use a weight belt.

My questions are,

1) Should I jump into the water wothout the weight belt and take the weight belt from the boatman and wear it after I put on my BCD? I remember doing it with my weight belt on during my OW. But I was told to remove my weight belt while on the boat by a DM 2 trip back. Reason being was, If i fall into the ocean, I will not sink. So, I'm confuse now.

2) If I am properly weight. Say i float eye level with full gear with a normal inhale. Will I sink with my weight belt without my rig if I jump into the water?

Thanks in advance for the feedback... Appreciate.

 

[diversteve]

Do NOT jump into the water with your weight belt on only. You most likely will sink. Your BC is providing buoyancy to keep that from happening when you're fully geared up. Depending on how much weight you're carrying, you may not be able to swim it back up to the surface. Freedivers sometimes use light weight to compensate for their/suit buoyancy but that's a different idea. Try it in a pool sometime.

The people doing it with weight integration have their rigs buoyant enough so when they throw them in the water they float by themselves. I've done it off small boats - we even tie them to the boat so they can't get away while re-boarding then haul them back on board.

On really small boats like Zodiac's we go off in pairs - one on each side to minimize the rocking. Suggest that to whoever is driving the boat. I've even done it where the whole boat back-rolls at the same time.

 

[Steve_C]

What diversteve said. There have been some very serious accidents when somebody took off their BCD to pass onto the boat and forgot they had a weight belt on. Have heard of rescues that went wrong for the same reason. You can have somebody pass you the belt after you put on BCD in the water.

 

[timz]

Do NOT jump into the water with your weight belt on only. You most likely will sink. Your BC is providing buoyancy to keep that from happening when you're fully geared up. Depending on how much weight you're carrying, you may not be able to swim it back up to the surface. Freedivers sometimes use light weight to compensate for their/suit buoyancy but that's a different idea. Try it in a pool sometime.

The people doing it with weight integration have their rigs buoyant enough so when they throw them in the water they float by themselves. I've done it off small boats - we even tie them to the boat so they can't get away while re-boarding then haul them back on board.

On really small boats like Zodiac's we go off in pairs - one on each side to minimize the rocking. Suggest that to whoever is driving the boat. I've even done it where the whole boat back-rolls at the same time.

Yeah. That's what we did. Those whom didn't wear the BCD on the surface back roll in pair including me.

But for discussion sake. Let say if we are properly weight with full gear floating at eye level when inhale normally. Will we sink without the BCD and tank.

What diversteve said. There have been some very serious accidents when somebody took off their BCD to pass onto the boat and forgot they had a weight belt on. Have heard of rescues that went wrong for the same reason. You can have somebody pass you the belt after you put on BCD in the water.

 

[tbone1004]

it depends on your bc and tank. Odds are yes.

Your weight belt does two things. Offsets your buoyancy *includes your exposure protection*, and offsets the weight of the gas in the tank. So for an AL80, that's about 6lbs. This means that if you are properly weighted using a traditional BCD, then you should be at minimum 6lbs overweighted on your weight belt if you don't have a rig on. Now, you should be able to safely stay at the surface being 6lbs overweighted, we require students to take a 10lb diving brick up from the bottom of a pool without fins on, but it's still not recommended.

 

[timz]

it depends on your bc and tank. Odds are yes.

Your weight belt does two things. Offsets your buoyancy *includes your exposure protection*, and offsets the weight of the gas in the tank. So for an AL80, that's about 6lbs. This means that if you are properly weighted using a traditional BCD, then you should be at minimum 6lbs overweighted on your weight belt if you don't have a rig on. Now, you should be able to safely stay at the surface being 6lbs overweighted, we require students to take a 10lb diving brick up from the bottom of a pool without fins on, but it's still not recommended.

Okay. Means even at 6lbs overweight, I should still be floating on the surface?

I'm using DR Travelpac.

But during the OW, I did the removal and wear traditional BC under the water with the BC fully deflate. The BC remains at the bottom. So, I think the BC is negative when fully deflate with a filled tank.

Correct me if I'm wrong.

 

[tbone1004]

no, you will not be floating at the surface. You should be able to stay at the surface by actively sculling your fins, but with a weight belt on, you will sink.

The BC should be slightly negative with a full tank. The tank with valve is about -1.4, the first stage is another -1.5, and the rig should be about neutral, so depending on how much air you have in the tank, it should be between 2-4lbs negative. That doesn't change the weight you have on your body though which is about 6lbs more lead than you need to be neutral in just your wetsuit to compensate for the air in your rig. This is one of the reasons that SS backplates are nice because the 6lbs on the backplate is the lead you need to offset the air in an AL80. Combine that with the extra weight from the regulator, etc etc and the diver without the rig should be positively buoyant which removes the need to ditch weight. Ditch the whole rig and you'll be high and dry at the surface.

 

[dumpsterDiver]

The answer should be that you really need to jump in with your suit on and your weight belt and mask and fins and snorkel... and see how it feels. do it in shallow water where you can stand up. If you are so heavy that it is at all hard to stay at the surface, then i would advise for you to move a small amount of lead to the BC.

I would be terrified of going in the water if I didn't know what would happen. As others have mentioned, if your weightbelt is correct, you should be able to snorkel around pretty easily.

This whole question amazes me actually. What if a whale shark shows up on the surface interval, don't you want to slap a weight belt on and mask fins and snorkel and check it out? Being able to do this at a moment's notice is one of the big benefits of using a weight belt and NOT 100% integrated weights..