wing size

[fjpatrum]

I'm curious about something. I use the wing calculator in the stickies to figure out the "required lift" I need. With 13mm suit, I list 20#s for buoyancy. Now, even overweighted (the sheet lists 17.4 pounds of lead and I only need about 15) the calculator shows I only need a 25# wing if the weights are integrated and 15# wing if not integrated. When I put lower numbers for my exposure suit, say 10#s the numbers all drop. If I change to double HP100s and add an 8# light I still only come up with 38# lift with integrated weights.

So, the question. Why would anyone need a 55# wing for a single, or even a 44# wing? I recognize that I use a lot less weight than some folks, but I don't see using 35 or 40 pounds of lead for anyone.

Am I wrong in this or are most people just buying way more lift than they actually need?

I'm curious why the smallest wing I've seen is a 25# wing if many people simply don't need such large wings?

 

[cool_hardware52]

So, the question. Why would anyone need a 55# wing for a single, or even a 44# wing?

They don't, but many believe more is better. They often don't understand proper weighting.

I recognize that I use a lot less weight than some folks, but I don't see using 35 or 40 pounds of lead for anyone.

It happens, but very rarely. Big guy with lots of neoprene or a PSD diver who's intentionally 10 lbs overweighted.

The largest singles wing DSS offers is a 40 and we sell very few.

Am I wrong in this or are most people just buying way more lift than they actually need?

Most divers have *way* more BC capacity than is necessary. Many are over weighted, but believe it's OK because they have a mondo BC.

I'm curious why the smallest wing I've seen is a 25# wing if many people simply don't need such large wings?

We offer a 17.

When confronted with a diver who's debating between too large and much too large I often point out that not too many years ago divers used *NO* bc's and somehow managed to survive.

Tobin

 

[horsediver1]

just a point to ponder as I use a large capacity back inflation BCD. I do not over weight as I am within 1-2 lbs of negative at the beginning of a dive being very neutral with the tanks emptying. From the PSD side is there are times when recovering evidence or bringing vehicles up that have crashed a diver may be carrying tools, primary axle chains stringing wrecker cable or a variety of above all with substantial weight. Thus needing the extra bouyancy. My only point is there is a purpose sometimes and really no rubber stamp answers i.e. PSD divers wear 10 extra pounds of lead.

 

[DiverLaura]

and that is a case of using the 'tool for the job'.

I think what a lot of us are saying is that a regular ole' joe shmo recreational diver (and even extended range recreational diver) should not need a zillion pounds of lift to float the standard rig, and in fact it becomes counterproductive.

I'm curious how you get 1-2lbs negative at the beginning of a dive and neutral at the end of a dive unless you only use about 1/3 of your gas and/or are using helium mixes OR are diving CCR. Swing weight of tanks (the weight of the gas you use from start to finish) doesn't vary depending on the amount of weight strapped on or BC used, its quite simply the weight of the gas consumed.

just a point to ponder as I use a large capacity back inflation BCD. I do not over weight as I am within 1-2 lbs of negative at the beginning of a dive being very neutral with the tanks emptying. From the PSD side is there are times when recovering evidence or bringing vehicles up that have crashed a diver may be carrying tools, primary axle chains stringing wrecker cable or a variety of above all with substantial weight. Thus needing the extra bouyancy. My only point is there is a purpose sometimes and really no rubber stamp answers i.e. PSD divers wear 10 extra pounds of lead.

 

[TSandM]

You can need more lift if you are carrying all your ballast on your rig, so you can float it at the surface; you can need more lift at the surface if you are diving big double steels and carrying a stage and a deco bottle. But even then, 50 lbs or so should do it.

 

[Biodiversity_guy]

I have a DSS, with about 300+ dives on it, up here in the NW. Great rig!

I am looking at moving into doubles, (HP 100) and was wondering what the rule of thumb was for "lbs of life needed" for the BC.

Tobin, I see your doubles BCs range from 38 to 57 lbs of lift. I do dry suit diving, Puget Sound. Medium height. What would you suggest? Is there a nice write-up some where you could point me to?

 

[cool_hardware52]

I have a DSS, with about 300+ dives on it, up here in the NW. Great rig!

I am looking at moving into doubles, (HP 100) and was wondering what the rule of thumb was for "lbs of life needed" for the BC.

Tobin, I see your doubles BCs range from 38 to 57 lbs of lift. I do dry suit diving, Puget Sound. Medium height. What would you suggest? Is there a nice write-up some where you could point me to?

The short answer is min wing capacity should be:

The weigth of your back gas, + the minimum buoyancy of your drysuit +~3 lbs.

With 2 x 100's you have ~16 lbs of back gas

If your suit is less than 30 lbs positive then a T49 is a good choice, more than 30 lbs positive suggests a 57.

Tobin

 

[Biodiversity_guy]

Thank you!