OP
Assembling first doubles rig: Looking for a starting point
- Thread starter AbyssalPlains
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OP
AbyssalPlains
Contributor
Hmm, I thought I was seeing clearer but I'm afraid I'm not so sure anymore. It seems a lot of people prefer the steel 100s, even when diving wet. I totally agree with those who say why compromise 80% of diving dry with Alu cylinders only because of 20% of wetsuit diving. On the other hand, doesn't going with steel cylinders in the same scenario mean optimizing the drysuit diving, but risking death in those 20% of wetsuit diving? My point is that I'm not so sure that being seriously overweighted with non-ditchable weight is just an inconvenience - I think it's a matter of potentially deadly risk. Am I worrying too much about this?
ianr33
Contributor
You're thinking like a recreational diver here. Ditching weight is not an option on a technical dive. How do you stop at 20 feet once your wetsuit has expanded?
If the extra weight you have to carry with Al 80's is not a problem I would suggest going with those. Cheap,don't rust,can always use them as stages/deco bottles down the road.
Obviously it depends on your SAC rate, but for me Al 80's with one deco bottle work for 130 feet for 25 minutes or 150 for 20. Add a second deco bottle and they're good for 200 feet for 20 minutes. Not too shabby!
LenC
Registered
I have no problem at all swimming my steel 100's from depth with no air in the BC. Admittedly, once I'm on the surface it is a different story but you can take them off and let them drop if it becomes a survival issue. The real problem I have with al 80's is that they are so light when they get low on gas that dropping your weights could well force you to blow off deco - whether intentionally or not. Ditching weight simply is not a luxury one can afford in deco diving. If you need doubles to do a dive, then you need to make sure you bring enough gas so you won't have to ditch weight.
Rainer
Contributor
Not sure I follow what you've written here. If swimming up HP100s in a wetsuit is causing you such issues that you can barely stay at the surface, how are you planning to hold extended deco stops along the way? I can't imagine getting up steels (especially with appreciable gas in them) in a wetsuit with a failed wing. YMMV.
To the OP, if you're diving wet without redundant buoyancy, the Al80s are probably your best bet.
To the OP, if you're diving wet without redundant buoyancy, the Al80s are probably your best bet.
I'm of the opinion that you should be in a drysuit in the first place, which would eliminate most of the questions and issues that arise from technical diving in a wetsuit.
Aside from that, like Ranier said AL80's are probably your best bet.
Aside from that, like Ranier said AL80's are probably your best bet.
Last edited:
Rainer
Contributor
AbyssalPlains,
Since Al 80's are ubiquitous, one option might be to simply rent two Al 80's and double them up (either with nylon travel bands or with SS bands) and dive them as independent doubles for the occasions when you are diving wet in warm salt water. This solution would work until you started needing a bottom gas other than air or recreational nitrox. And this solution would free up your cash so you could assemble a set of isolation-manifolded HP100's for dry suit diving in cold water (if this is what you want and if cash is a consideration).
Safe Diving,
Ronald
Since Al 80's are ubiquitous, one option might be to simply rent two Al 80's and double them up (either with nylon travel bands or with SS bands) and dive them as independent doubles for the occasions when you are diving wet in warm salt water. This solution would work until you started needing a bottom gas other than air or recreational nitrox. And this solution would free up your cash so you could assemble a set of isolation-manifolded HP100's for dry suit diving in cold water (if this is what you want and if cash is a consideration).
Safe Diving,
Ronald
kanonfodr
Contributor
Maybe, but not everyone needs that option. Here in Hawaii we have people who are just fine for an hour in the water in a rashgaurd and boardshorts: that's a 30-minute technical dive to 150 or so with deco. Should we penalize folks for being warm-blooded??
Peace,
Greg
I've never dove in openwater that warm. But I have spent extended time in pools in that range, and yes, over enough time, I did get cold.
I dive dry. And even in warm water, I'd dive dry. Unless the water temperature is equal to body temperature, over time body temperature will be lost. It also eliminates the question about redundant bouyancy that arose earlier.
Again, this is just my opinion. That's what I would recommend. You can do it however you want.
I dive dry. And even in warm water, I'd dive dry. Unless the water temperature is equal to body temperature, over time body temperature will be lost. It also eliminates the question about redundant bouyancy that arose earlier.
Again, this is just my opinion. That's what I would recommend. You can do it however you want.
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