Doubles and a Wetsuit in the NE

[tomfcrist]

Al100's have virtually the same buoyancy characteristics as the 80's.....that being said I prefer 120's for doubles because most of my dives on doubles are deeper/longer than usual.

Are the AL100's you are using the 3300 PSI fill pressure ones?

I don't use them, but have friends that do, and yes they are the 3300psi ones. They are negligibly heavier than 80's and are positive at the end of the dive.

 

[macado]

If you're really worried why not just carry a 50# lift bag. I keep one bungeed to my backplate; Simple solution to the problem. Alternatively I suppose you could purchase a double bladder wing but I dont like the bulk of those.

I usually dive my double 100s with a drysuit but occasionally use them with my farmer john wetsuit in a pinch. It's a risk I am willing to accept provided I have tools in case of a wing failure (I always carry lift bag & large SMB with reel)

 

[Dr. Lecter]

If you're only worried about swimming -20 or so lbs up from depth with good fins and average or better leg strength, I say knock yourself out...it's just not that hard, especially since your suit will expand as you ascend, cutting the negative weight. I know for a fact I can kick full double 130s up from 100'+ if I need to, and I NDL dive steel doubles in little to no exposure protection accordingly (though I always have a large, closed circuit SMB on me because I need it for emergencies unrelated to wing failure).

If you're getting into any kind of deco schedule, forget it--some kind of redundant buoyancy that will allow you to complete your stops should the wing fail is absolutely mandatory. That means an extra wing, a double bladder wing, and/or a SMB with sufficient lift and a closed circuit/OPV design for reliability and easy venting. I deco dive wet in steel doubles, but only with at least one form of redundant buoyancy that I've actually used to complete an ascent schedule before.

It also depends on where you're doing this; I wouldn't attempt it on a wall dive where there's no relevant bottom.

 

[cbrich]

Largest set of doubles would be Faber LP120s, since they are just over 1 pound more negative than double Faber LP85s.

 

[lowviz]

...//... a drysuit is out of the picture. Want to make a larger set of doubles so that we are only bringing one set-up to the shore or boat. ...//...

I just don't see that happening for two decent dives.

...//... If I need more gas I add a stage ...//...

Same.

Yeah the double 72s just dont have enough juice for 2 dives . ...//...

If you can get a 2800-3000 psi fill, they are quite nice tanks for one dive. Why not sling an AL80, breathe it down to 2/3's on the first dive then go to the backgas. Second dive, breathe the AL80 down to 1/3 then breathe the backgas down to your reserve? This rig would also offer you true redundancy.

Add a crotch strap if you don't already have one and put a tailpiece on it. An AL80 will ride much more 'out of the way' if clipped off to a tailpiece rather than clipped to your hip D-ring.

 

[Scared Silly]

Largest set of doubles would be Faber LP120s, since they are just over 1 pound more negative than double Faber LP85s.

Yeah buoyancy differences are not much but damn the dry weights are another ~26 lbs. Arrg by the time one is kitted up ya got over 100 lbs of on yer back.

 

[cbrich]

Yeah buoyancy differences are not much but damn the dry weights are another ~26 lbs. Arrg by the time one is kitted up ya got over 100 lbs of on yer back.

Yeah, carrying the big LP and HP tanks is not for the weak.