BP/W- question on size of wing

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granolatree

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Location
Alaska
Today, my husband and I were in a LDS talking to the owner about BP/W set ups. We were checking out the OMS comfort harness and were quite impressed by it (fit, comfort, quality, etc). The owner suggested that my husband (being 6'3" and 250 lbs) get the 60 lb wing. From the research we have conducted, this seems to be a little excessive. Are we wrong to think this?

We are going to buy the OMS comfort harness with SS back plate (which is 6 lbs.).

We both have the Pinnacle 8mm wetsuit with hood.

We will be diving with single HP 100s, and plan venture out on the occasional dry-suit trip in Alaska.

From all the research we have done on this board and other sites, a 32 lb. wing with wetsuit seems to be sufficient. Is this just our naivety rearing it's ugly head, or should we go with the 45 or 60 lb. wings?

Thanks in advance!
Kate
 
Please do a search - this has been discussed many times before on SB.

60 pounds is extremely excessive. 32 will be fine.
 
Please do a search - this has been discussed many times before on SB.

60 pounds is extremely excessive. 32 will be fine.

32 may be fine in Australia, but may not be fine in Alaska where the owner will be diving in a drysuit with 30+ pounds of lead.

Terry
 
A 60# wing is excessive for a single tank set-up. If you want to stay with OMS products, then the 32# or 45# wings that they have should be sufficient. Good luck with your decision.
 
Kate is there a possibility of you having a dive with the comfort harness before you buy because I had an OMS IQ pack for a long time, I then switched to a comfort harness and found it to be less than comfortable and I ended up buying another IQ pack.

I have now been using a BP and one piece webbed harness for a while and it is so much more comfortable than anything else.

I would also agree about the wing, I used to dive with an OMS 94lb wing and had the OMS 32lb travel wing for holidays, I now have a 40 for twins and a 30 for singles.
 
Today, my husband and I were in a LDS talking to the owner about BP/W set ups. We were checking out the OMS comfort harness and were quite impressed by it (fit, comfort, quality, etc). The owner suggested that my husband (being 6'3" and 250 lbs) get the 60 lb wing. From the research we have conducted, this seems to be a little excessive. Are we wrong to think this?

We are going to buy the OMS comfort harness with SS back plate (which is 6 lbs.).

We both have the Pinnacle 8mm wetsuit with hood.

We will be diving with single HP 100s, and plan venture out on the occasional dry-suit trip in Alaska.

From all the research we have done on this board and other sites, a 32 lb. wing with wetsuit seems to be sufficient. Is this just our naivety rearing it's ugly head, or should we go with the 45 or 60 lb. wings?

Thanks in advance!
Kate

Kate,

Any BC needs o meet two criteria. It needs to offer enough lift to float your rig at the surface with a full tank if you ditch it, and it needs to be able to compensate for the maximum change in buoyancy of your exposure suit.

In cold water the buoyancy of your exposure suit will likely determine the wing size, and could also impact the maximum negative buoyancy of your rig.

The size / weight of the diver plays no part in wing selection, other than how it impact the size of the exposure suit.

How buoyant are your exposure suits? Roll them up and put them in the water and add lead until it just sinks. Weigh the lead. That the "initial" buoyancy of the suit.

Your exposure suit cannot loose more buoyancy due to compression than it starts with at the surface.

****This is just an example, your numbers will likely vary****

I'll assume that your husbands "8mm" suit is 25 lbs buoyant. I'll assume you are using PST E7-100 tanks. These tanks are -1 lbs empty, and -9 full. If you are using other tanks find out what their buoyancy is. Google "Scuba Tank Specifications"

A SS back plate and harness is about -6 lbs. A regulator is about -2 and we have assumed your tank is -9 full. That means your rig will be about -17 with a full tank, and will provide about -9 lbs of ballast with an empty tank.

If your exposure suit is +25 and your rig provides 9 lbs of ballast you will need another ~14-16 lb of lead. You can put this 14-16 lbs in a weight belt, or put some of the weight on the rig. I'll assume you choose to put 8 of the 14-16 on the rig via weight pouches on the harness or weight plates, or a "P weight" etc.

Now your rig, with a full tank will be 17 + 8 = 25 lbs negative.

To float your rig you need a wing bigger than 25. A ~30 would work fine. To compensate for a fully compressed wetsuit you need a wing bigger than 25 lbs also, here again a ~30 would work fine.

How buoyant would your exposure suit have to be to need a 45 or a 60 lbs wing?

Over sized wings add drag, and are more difficult to vent than a well designed wing of appropriate size. Buying a huge wing will negate many of the advantages of using a BP&W.

Go test your suits, and research your tank's buoyancy. Be prepared when you shop for your next BC.

Tobin
 
32 may be fine in Australia, but may not be fine in Alaska where the owner will be diving in a drysuit with 30+ pounds of lead.

Terry

Not sure what your perceptions of Australia are, but they sound pretty inaccurate. We do not wear 3mm shorties year round here.

I dive a drysuit and a steel 100 with 30 pounds of lead over here and a 30# Mach V is plenty of lift for me.
 
Not sure what your perceptions of Australia are, but they sound pretty inaccurate. We do not wear 3mm shorties year round here.

I dive a drysuit and a steel 100 with 30 pounds of lead over here and a 30# Mach V is plenty of lift for me.

A full steel 100 is about 9 pounds negative when full (depending on the cylinder) and your 30 pounds of lead is about 30 pounds, and your plate is most likely negative by some amount, so surfacing with a flooded suit would seem to be a problem.

I'm not trying to sell big wings (I don't sell anything), and you can certainly dive whatever you want, but it always bothers me to find people who don't have enough lift to float themselves in an emergency, or keep a buddy's head out of the water in case he has a problem.

Terry
 
It is good that you discuss these issues. I guess it doesn't matter if you have a neoprene suit or a shell drysuit, flooding either can pose a problem. I imagine that a neoprene suit would lose buoyancy at depth from compression, and if flooded, will give you better buoyancy than a shell drysuit. But in either case, you'd want some assistance from your BC or it would be alot of work to get to the surface. I've noted that if I emptied my BC and try to swim up with 24 lb of lead and a doubled wet suit (14 mm at the trunk), it sure is alot of work, even if the suit balance out the lead near the surface.
 
A full steel 100 is about 9 pounds negative when full (depending on the cylinder) and your 30 pounds of lead is about 30 pounds, and your plate is most likely negative by some amount, so surfacing with a flooded suit would seem to be a problem.

I'm not trying to sell big wings (I don't sell anything), and you can certainly dive whatever you want, but it always bothers me to find people who don't have enough lift to float themselves in an emergency, or keep a buddy's head out of the water in case he has a problem.

Terry

I agree Terry. If a diver needs 30 lbs of ballast + Backplate + Regular + a negative (when empty) steel tank, then you can assume that their exposure suit is 35 + lbs positive. (That alone is a bit unusual, very few exposure suits are more than 30 lbs positive)

If a diver is using a suit that is 35+ lbs positive he should use a BC with at least that much lift capacity.

Tobin
 

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