Does this BC product exist?

[GreenDiverDown]

If I were going to buy a bp/w which one would you recommend?

Now THAT'S funny. I don't care who ya are!

 

[GreenDiverDown]

Don... watch out for Tim... He's crafty.

... slippin' in a pic of Pug... like we wouldn't know! Give us a break, Tim

 

[GreenDiverDown]

Ya know, Tim, the right guy can make anything look good.

Hmm... I got a shot of GI3 in one of them Outrigger contraptions... Oh, where did I put it?

 

[TheRedHead]

Stephen, 2 more posts to go and you're at 1800!

 

[Walter]

You still have to think about trim with air in the bladder and how that affects your position in the water. It's the heads up position that causes the most drag.

Actually, if you have a heads up position, you have bigger problems than drag. A heads up position is caused by being over weighted - using any BC - including a BP/wing. When overweighted, you are tranferring some of your forward thrust into upward thrust to keep you from sinking. If you have a heads up attitude, lean forward and add air to your BC.

Drag is caused by bulk. Some of it is unavoidable, but you should eliminate all of it you can. Fabric covering of a bladder is a large source of drag that can be eliminated. So is any padding in your BC. Padding is really bad - it adds drag and requires you to carry more lead.

 

[TheRedHead]

Actually, if you have a heads up position, you have bigger problems than drag. A heads up position is caused by being over weighted - using any BC - including a BP/wing. When overweighted, you are tranferring some of your forward thrust into upward thrust to keep you from sinking. If you have a heads up attitude, lean forward and add air to your BC.

Some divers are diving in 7mm farmer johns and are overweighted to compensate for the neoprene. They pump air in the their jackets and go heads up. Maybe I associate jackets with overweighting and bad trim because I used to wear one as a new diver and haven't worn it in years. It never fit me properly and I never acheived good trim with it.

 

[Walter]

Some divers are diving in 7mm farmer johns and are overweighted to compensate for the neoprene.

I dive a 7 mm full suit in the winter, I understand that as you descend, you become overweighted because of wet suit compression. Adding air to the BC compensates for this. Adding almost enough air almost compensates for it, so they are still overweighted which results in them having a heads up attitude while swimming forward. If they stop kicking, they'll sink.

Maybe I associate jackets with overweighting and bad trim because I used to wear one as a new diver and haven't worn it in years. It never fit me properly and I never acheived good trim with it.

Most instructors are incompetent, so most new divers don't even know they are overweighted nor that they should strive for a horizontal position while swimming. They have not come close to mastering buoyancy control. Most of the folks I see wearing vests are poor divers, but I see a few that are incredibly good. A well designed BP/wing is an excellent choice for a BC, but so is a well designed vest. I must admit, well designed vests are getting harder to find.

 

[kidspot]

As has been often (though not often enough) stated here on the board, "it's the diver in the gear, not the gear on the diver" ... that's the most important thing.

Aloha, Tim

 

[TheRedHead]

All I can say is that if it fits poorly enough - it can be the gear! My jacket rode up because the cumberbund would never fasten tightly enough and the sternum strap hit me in the throat. It made good trim impossible for me.

 

[Thalassamania]

We have a lot of noise and claims, but no data. About fifteen years ago a chap named Steve Paulett did a bunch of tow tank studies on BCs. His finding was that the jacket style BC had the least drag. Now, "modern wings" were not available for testing then, so the closest things to wings were AT-Pacs and similar back-mounted wing BCs. You can download Dave's History of BCs which addresses Steve's work a little. But the fact remains that empirical testing showed that the claim of wings having less drag are simply not true. If there are more recent studies, I'm open to to them.