How much BC lift do I require?

[Aegir]

Ok guys thanks very much for your help and advice on my question I appreciate your opinions. Today I talked to my Instructor who is a technical diver and 6 other techy divers who have all been on british expeditions at some point or another. They all regularly dive over 80 metres and are extremely experienced trimix divers also, so there advice was not taken lightly. Apparently diverite just isnt up to the job, according to these guys, and other independant techies I have spoken to feel the same way. I will be going with Custom divers kit which happen to be a British made brand, so you people in the USA might not have heard of them.
http://www.customdivers.com

 

[MrMrEZG]

where a back just will not work no matter what you try. that is when a DM or INST is donning his/her bc in front of students. I have seen this from both sides of the table. so other than the classroom a backplate should work for you.

 

[Iguana Don]

"Technical Diving" is as much a philosophy as it is an art and skill.

Whichever philosophy you follow will determine which kind of gear you use. Some prefer Diverite, some prefer OMS, some prefer Halcyon and others. Your particular instructor chooses to follow "Others", which doesn't make them right or wrong, it just makes them different.

You have asked for opinions here and have gotten some execellent ones, obviously they are contrary to your instructors. In that case you have to make a decision.

IMHO you need to do some more studying and research on the topic and decide which philosophy you are going to follow before making any equipment purchase. Also it is imperative that the equipment you use is like the equipment your buddy uses, as down deep or inside the bowels of a cave you don't have the time to "try and figure out" how your buddy is rigged. If you are all rigged the same, all actions in an emergency come from instinct rather than choice. This is from GUE philosophy of "Technical Diving".

I tend to follow this one as it seems to make the most sense and their experience and accomplishments are the most documented and critiqued.

Just my .02

ID

 

[ericfine50]

Don,

I agree with you 100%. Having the entire team rigged out the same is so important. Everyone knows were the same piece of gear is one everyone else. Another important thing is to be diving the same gas mixes. Having the "standard" gases helps with deco planning and makes things simpler in the long run.

When I suggested Halcyon, it is not because they are DIR (I dive DIR), but after seeing OMS gear on a dive boat I worked on in the Northeast US, seeing how it did not work and the drag associated with it, I know that was bad. Then I looked at DR, Loved the old style wings, only problem - not beefy enough - then Halcyon came out and they made a wing (and other gear) that had those small things I was looking for. Their gear for 2001 looks even better.

Check out GUE at http://www.gue.com and log onto the Quest forums (free) and search for answers Aegir to help your gear selection a little more.

Eric

 

[turnerjd]

Aegir,

Lots of poeple have very strong opinions about gear config as to what is right and what is wrong.

IMO what you are happy with is best for you. I personally don't think that unless you are going to go beyond the BSAC 50m level you need a very techie setup.

Buddy sell the 'Redwing'. This is a wing that fits between the fabric of a normal jacket, and the rear molded plastic plate the tank rests against. This can be fitted to practically ANY BCD. I have one attached to my Scubapro jacket, and my 15Kg odd lift from that is not 37Kg or so. Yes it means as extra hose, but it doesn' mean an extra BCD!

If you have found a Jacket that you are happy with investigate fitting something like the redwing to it. I saw the redwing for £123 at the diveshow, so it isn't that expensive!

The buddy redwing is what they use on the Inspiration rebreather, so no techie can accuse you of not using techie kit!

Jon T

 

[Aegir]

Is there a formula you can use to work out the amount of lift you will need from a wing/bcd?

Thankyou

 

[detroit diver]

You need to know how negative you are in your dive. How negative is the BCD/backplate? How much weigh on your belt/pockets? What does the tank weight full? Keel weights? Ankle weights? Computer? Camera? Light?

Add these up and you should get a pretty good number to start out with. Then size it just on step larger for safety, IMHO.

If you're planning on changing your equipment any time soon, then size your wing for that also, within reason.

 

[Aegir]

Thanks detroit diver but i know exactly how to work out how much weight i have, i just wondered if there was a mathematical formula to give a *rough* estimation of how much lift is reguired for a said quantity of weight.

 

[Atomox]

1 cubic foot of fresh water is equal to 62.4 lbs

 

[herman]

Is it not 1 to 1? I would think that if I needed to lift an object that weighed 10lbs, then I would need 10lbs of lift to get it to neutral.....Think I need a search and recovery class....