Diving Doubles in Salt water

[DA Aquamaster]

I dive double Steel all the time in a wetsuit, as I rarely dive dry. LP 51's, LP 85's, and or HP 100's.

If you're worried about a complete wing failure, try (and practice occasionally if needed) using your lift bag as your backup for buoyancy compensation (if and only if it has an exhaust valve) so you can easily vent on the way up.

"If you're worried" is key. To put it in perspective a complete wing failure is rare and involves something like a failure of the corrogated inflator hose near the elbow or a failure of the elbow itself. I have seen new OW students actually pull them out of a BC due to overzealous attempts to dump. but technical diving wings do not as a rule have elbows that incorporate a dump valve - reducing any need or tendency to pull on it and also elimintating the dump valve as a potential failure point.

The bottom dump/OPV valve on a wing is located low on the wing so even if it were missing entirely the wing would still hold most of it's rated lift in a vertical position.

In short, unless you tear a large hole near the top of the wing (something that is largely avoidable with reasonable care) a complete failure is extremely unlikely. I have had one wing failure in about 15 years of diving with various wings and that involved a faulty OPV - but the wing still provided more than enough lift in vertical ascent position.

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An alternative to using the lift bag as a field expedient BC is to shoot the lift bag to create an upline then climb or reel yourself up the line. It takes less practice and has no risk of a run away ascent.

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In light of the above, I also routinely dive steel doubles in a 3mm wet suit - I just ensure I have at least one lift bag bungeed to the bottom of the plate and have a safety spool along.

 

[Indian Valley Scuba]

Steel HP 100's are the most popular setup with our divers, including myself. They are physically smaller than LP 100's and therefore have a lower center of gravity on your back, making the rig a bit more stable. I dive a variety of drysuits in saltwater, including the Whites Fusion, and use no additional weight with the 100's. In fresh water they are a bit heavy, buoyancy-wise, but in salt they are perfect!

For a quick reference and comparison of tank dimensions, weights and buoyancy characteristics, check out this handy guide.

 

[TSandM]

I dive a variety of drysuits in saltwater, including the Whites Fusion, and use no additional weight with the 100's.

Oh, that would be SO nice! I have to use 24 pounds of ballast with double 100's . . . the price of insulation for 43 degree water

 

[Indian Valley Scuba]

Dude - we need to get you some more efficient undergarments or help you with your thermal tolerance! I dive the same temperatures here in the Northeast US, and you see what weight I need to wear!

What sort of loft are you packing under that suit?

 

[David_57]

I dive double HP 100's on a s/s backplate use 8 lbs when diving in cold water with in a drysuit and a thick under layer, probably a bit over weight as I like to add extra air in my drysuit to help keep warm.

I have not tried them in warmer water say in the mid 60's with just a tee shirt and long johns underneath my drysuit but hoping I should need very little if any weight.

 

[DA Aquamaster]

I also dive double X7-100s with a 6 lb SS plate and a Fusion and need no weight in mid 40 degree salt water. I normally wear a set of Tilos undergarments with a layer of off the shelf Gander Mountain or Rocky polypro fleece on top.

 

[TSandM]

Well, I start out pretty buoyant -- I don't have to tread water, I can just sit there and watch the guy with the timer.

Under my Fusion, I use a layer of 4th Element Dry base, a 200g Thinsulate vest, and the White's MK3 undergarment, with two pairs of fluffy fleece socks. And my ballast has been repeatedly weight checked, because I keep hoping that somehow, I can cut it down . . . Oh, and I weight for 3 - 400 psi tanks, not for the gas I plan to use, and that makes some difference.

 

[black1]

I dive my Steel HP 120 in a 3mm w/3mm vest/hood attachment in 80 degree water and no weight at all, im slightly overweighted and do just fine, soon to have a Fusion and will do the same.

 

[Blackwood]

Steel HP 100's are the most popular setup with our divers, including myself. They are physically smaller than LP 100's and therefore have a lower center of gravity on your back, making the rig a bit more stable. I dive a variety of drysuits in saltwater, including the Whites Fusion, and use no additional weight with the 100's. In fresh water they are a bit heavy, buoyancy-wise, but in salt they are perfect!

Odd.

I wear a DUI 300g bunny suit under my TLS350, and I need about 8# on top of my steel plate, and I need it low (5 in a tail pouch, three in a soft v-weight). If I took off the weight, I would be fighting head-down trim (in double HP100s).

 

[Indian Valley Scuba]

Well it looks like you are pretty thin, and possibly a bit tall, from your photos. That tends to be a problem with weighting, as your ratio of bio-mass inside the undergarments vs the volume of the undergarments themselves is more favorable to being quite positive. People with more "meat" inside the undergarments only add a smaller increase in curcumferance to the suit, so the ratio starts to get more towards neutral. That probably explains your need to carry additional lead. But better to be thin and carry lead than the alternative!!

And, after looking at the photo and profile, may I apologize for the 'dude' comment! Oooops!