Codyjp
Contributor
I sent Tobin a pm regarding selecting a wing for HP100 doubles. The response I got (in half a business day) was great, really where else can you get this type of service and customer support from? He allowed me to post it here as it can probably help some of you too!
Thanks again Tobin!
Quote:
Originally Posted by Codyjp
Tobin, It is time to buy my LCD30 a buddy since i am moving to doubles.
I am getting a set of PST100's. I currently dive with a TLS350 here in socal.
what would you recomend for a doubles wing? I don't see the need for tons of lift (50+) but I may be wrong on that. I don't see jumping in and getting deco tanks and all that mess for a long while.
I also think i may want a donut wing instead of a horseshoe wing this time too so I can allow the air to pass around the bottom when I am exhausting it. What do you think?
Anyway, you are the pro at this. No hurry either if you are busy.
Thanks for your help,
Cody
His Reply-->
Cody,
As with singles, a wing for doubles is function of the buoyancy of your exposure suit, and the volume of the gas you are carrying.
Deco / stage bottles should not really impact this very much. They are ditchable after all.
You need to start a potential deco dive negative by the weight of your back gas, + 2-3 lbs extra.
This extra weight allows you to "fluff up" your dry suit at your shallow stop, while you fully drain your back gas.
If you should ever have hang for an extended stop (lost deco gas etc.) you don't want to have to do it in a shrink wrapped dry suit, burr!
With 100's you have about 16 lbs of air or nitrox. 16 +3 = 19. That means just to stay eyelevel at the start of the dive you need to use ~19 lbs of the capacity of your wing.
Now add a total dry suit failure. Unlikely, but not impossible. If you cannot trap gas in your dry suit you could possibly loose all the buoyancy it provides. You cannot loose more.
How buoyant is your drysuit with minimum gas in it? If you put on just your undies and suit and got into neck deep water and vented your suit as much as possible in neck deep water how much lead would you need to be neutral?
I'll guess here and say 25 lbs. You should either test your suit, or examine your current single rig and figure it out.
19 + 25 = 44 A 44 lbs lift wing would in theory provide enough lift to offset the 19 lbs you will negative by, and a complete failure of your suit.
Now lets take a look at your rig.
Empty 100's are about -3lbs (for a pair) band and manifold are about -5 lbs , dual regs are about -5, can light -2, medium SS plate and harness about -6.
With empty bottles your rig provides about 21 lbs of ballast, and with full tanks will be about -37. If your suit is really +25 you will need another ~4 lbs.
I'll assume you add this ballast to your rig. That makes your rig about -41 lbs.
At -41 lbs my recommendation would be our Torus 49 wing. It offers a little margin for larger tanks (more gas weight) and it is also a "top biased" wing with more lift near your shoulders. That's often a help for new doubles divers.
I would not get to hung up on donut vs horseshoe style. (the Torus is a donut BTW)
You vent a wing during ascents. The last part of any donut wing to inflate is the lower arc, as it is the lowest. To be able to vent your dry suit you have to ascend slightly shoulder high, and your wing will equalize through the top arc when you vent your suit.
Call me if you have questions. 626-799-5074
Tobin
Thanks again Tobin!
Quote:
Originally Posted by Codyjp
Tobin, It is time to buy my LCD30 a buddy since i am moving to doubles.
I am getting a set of PST100's. I currently dive with a TLS350 here in socal.
what would you recomend for a doubles wing? I don't see the need for tons of lift (50+) but I may be wrong on that. I don't see jumping in and getting deco tanks and all that mess for a long while.
I also think i may want a donut wing instead of a horseshoe wing this time too so I can allow the air to pass around the bottom when I am exhausting it. What do you think?
Anyway, you are the pro at this. No hurry either if you are busy.
Thanks for your help,
Cody
His Reply-->
Cody,
As with singles, a wing for doubles is function of the buoyancy of your exposure suit, and the volume of the gas you are carrying.
Deco / stage bottles should not really impact this very much. They are ditchable after all.
You need to start a potential deco dive negative by the weight of your back gas, + 2-3 lbs extra.
This extra weight allows you to "fluff up" your dry suit at your shallow stop, while you fully drain your back gas.
If you should ever have hang for an extended stop (lost deco gas etc.) you don't want to have to do it in a shrink wrapped dry suit, burr!
With 100's you have about 16 lbs of air or nitrox. 16 +3 = 19. That means just to stay eyelevel at the start of the dive you need to use ~19 lbs of the capacity of your wing.
Now add a total dry suit failure. Unlikely, but not impossible. If you cannot trap gas in your dry suit you could possibly loose all the buoyancy it provides. You cannot loose more.
How buoyant is your drysuit with minimum gas in it? If you put on just your undies and suit and got into neck deep water and vented your suit as much as possible in neck deep water how much lead would you need to be neutral?
I'll guess here and say 25 lbs. You should either test your suit, or examine your current single rig and figure it out.
19 + 25 = 44 A 44 lbs lift wing would in theory provide enough lift to offset the 19 lbs you will negative by, and a complete failure of your suit.
Now lets take a look at your rig.
Empty 100's are about -3lbs (for a pair) band and manifold are about -5 lbs , dual regs are about -5, can light -2, medium SS plate and harness about -6.
With empty bottles your rig provides about 21 lbs of ballast, and with full tanks will be about -37. If your suit is really +25 you will need another ~4 lbs.
I'll assume you add this ballast to your rig. That makes your rig about -41 lbs.
At -41 lbs my recommendation would be our Torus 49 wing. It offers a little margin for larger tanks (more gas weight) and it is also a "top biased" wing with more lift near your shoulders. That's often a help for new doubles divers.
I would not get to hung up on donut vs horseshoe style. (the Torus is a donut BTW)
You vent a wing during ascents. The last part of any donut wing to inflate is the lower arc, as it is the lowest. To be able to vent your dry suit you have to ascend slightly shoulder high, and your wing will equalize through the top arc when you vent your suit.
Call me if you have questions. 626-799-5074
Tobin
