New BC Lift Question

[TravelSimone]

Hi, I am looking to buy some gear, and have a concern about BCs and lift. I have tried to read most of the old threads on BCs and lift, but still need some help.

I am primarily a tropical diver. I am 5'5" and my weight has been known to fluctuate from 125 to 138 (as much as I hate to admit this fluctuation :light: ). I get cold easily, so often wear a shorty 3mm, full 3mm or even a 5mm. I almost never dive in cold water. I will always be a vacation diver- a few trips a year. (The central California coast is too cold for me to become a weekly diver). I don't see myself getting into serious technical diving. All of my diving tends to require air travel, and therefore, I prefer that my BC not be very heavy.

I am looking at women's BCs and notice that some of them (size small) have a lift of 20 or 21lbs. I am wondering if I am going to regret not having more lift at some point in the future. I realize that everyone's gear set-up and bodies are different, but I'd love to have some input or suggestions with respect to women's BCs and a basic amount of lift that will not seriously limit me in terms of my recreational diving, but keeping in mind that I will be packing and carrying that BC around with me (so size/weight is going to matter).

Thank you for any advice you have to give.

 

[Doc Intrepid]

A BC offering between 20 and 30 lbs of lift should work well for you, Simone. How well it fits you, and how comfortable you feel in the water, are more important than the exact amount of lift it will provide (which - as you noted - will also be impacted by whether you're wearing a wetsuit or just a skin, etc.) (That is, the BC itself will not vary - but at the surface you may note some differences depending on what else varies!) I recommend you try a number of different options before you settle on one. Rent or borrow, the more you've tried (in the water) the more likely you will be to be satisfied with the one you eventually purchase.

Welcome to ScubaBoard.

 

[Jeff Toorish]

What BCDs are you looking at?

There is another solution, of course, going with a Backplate and wing. That way, you can choose exactly which wing and how much lift you use.

Jeff

 

[cool_hardware52]

Hi, I am looking to buy some gear, and have a concern about BCs and lift. I have tried to read most of the old threads on BCs and lift, but still need some help.

I am primarily a tropical diver. I am 5'5" and my weight has been known to fluctuate from 125 to 138 (as much as I hate to admit this fluctuation :light: ). I get cold easily, so often wear a shorty 3mm, full 3mm or even a 5mm. I almost never dive in cold water. I will always be a vacation diver- a few trips a year. (The central California coast is too cold for me to become a weekly diver). I don't see myself getting into serious technical diving. All of my diving tends to require air travel, and therefore, I prefer that my BC not be very heavy.

I am looking at women's BCs and notice that some of them (size small) have a lift of 20 or 21lbs. I am wondering if I am going to regret not having more lift at some point in the future. I realize that everyone's gear set-up and bodies are different, but I'd love to have some input or suggestions with respect to women's BCs and a basic amount of lift that will not seriously limit me in terms of my recreational diving, but keeping in mind that I will be packing and carrying that BC around with me (so size/weight is going to matter).

Thank you for any advice you have to give.

Any BC should meet to criteria; enough lift to float your gear at the surface without you and your buoyant exposure suit in it, and

Compensate for the compression of your exposure suit.

You can estimate the negative buoyancy of your rig by adding the negative buoyancy of the components, i.e. full cylinder, backplate if your using one, a few lbs for your reg, and any ballast you might attach to your rig (like integrated weights) There are numerous "tank spec" charts on the net. Google "scuba tank specifications"

The second thing you need to know is the intial positive buoyancy of your heaviest exposure suit, i.e. your 5mm suit. If you take your complete exposure suit and roll it up and throw it in the pool you can add lead until it just sinks. Weigh the bag o lead.

This represents the initial buoyancy of your suit, and also represents the maximum buoyancy you can looose as you decend.

Here's and example, it's only an example, you need to use your own numbers.

Typical rig:

Full AL 80 ~2 lbs

Regs ~2 lbs

SS Backplate ~6 lbs
(or integrated)
Misc ~2 lbs

Total example rig 12 lbs


Initial buoyancy of 5 mm full suit (just a guess) 14 lbs.


In this example the suit (14 lbs) is greater than the rig (-12) so you would need a BC with 14 or more lbs of lift.


Tobin

 

[TravelSimone]

What BCDs are you looking at?

There is another solution, of course, going with a Backplate and wing. That way, you can choose exactly which wing and how much lift you use.

Jeff

Thank you all for such fast replies.

I actually haven't narrowed the BCs down to just a few. I have been looking at the specs of a large variety of BCs and note that a number of small size women's BCs have less lift. In addition to fit and comfort, I am trying to narrow down the "playing field" of my search and was wondering if I would regret a BC with a lift of 20lbs. If advice suggests that I might be better off with a minimum lift of 25lbs, then I will stop looking at the BCs with less lift.

Last year I almost bought the Oceanic Isla- I liked the fit and it seemed fine for the diving I do (and small enough to make it easy to travel with). I never made the purchase and am now looking again. I note that Oceanic has come out with the Hera (which looks to be a replacement for the Isla). The small Isla (as I recall) has 20lbs of lift and the Hera has 36lbs. That is a fairly big discrepancy. Note that I am not committed to an Oceanic BC- I was only using this as an example of my search and lift questions.

As a side note, I am planning a fairly big trip to Indonesia and Malaysia in March, so hope to have some gear to haul around with me on this upcoming trip.

 

[DiveMaven]

I weigh quite a bit more than you and dive in a 5mm full suit with a Zeagle Zena with 24 pounds of lift. I have more than enough lift in my Zena for warm water diving, though if I were to dive cold, I'd get the bigger wing for that.

If you haven't checked out the Zena, it might be worth a look for you. It packs up very small and weighs only about 5 pounds. Great for travel!

 

[djanni]

My wife has an Isla. She has about 150 dives on it and she loves it. We've dived with single steel 95's and it's 23 lbs of lift is just fine. Hers is medium.

 

[TravelSimone]

snip

If you haven't checked out the Zena, it might be worth a look for you. It packs up very small and weighs only about 5 pounds. Great for travel!

I like the sound of 5 pounds. I should probably considering trying on the Zena. Thanks. All suggestions are welcome.