1st doubles dive and my thoughts...

[jim T.]

Hopefully my personal info. below will help you to decide what you'd like to do/try...
I've only had 3 dives in doubles so far. (dives 57,58 and 59).
One in generously lent LP85s and two in my own HP100s. I had very severe (and realistic) concerns regarding whether or not I should/could even handle doubles due to a spinal fusion of 30 yrs. ago and a "tricky" back as a result.

I've been pleasantly surprised that the HP100s (I'm 5ft. 11 & 3/4" 195lbs.) have been ok for sand beach shore dives. Haven't had to climb rocks yet, but did have to step over a couple of 2' dia. floating logs with 'em. I may throw my back out yet, but I'm hopeful it's all gonna be ok. I HAVE been weightlifting doing squats and deadlifts and lat/shoulder work which I highly recommend for self preservation

I still have concerns about climbing a boat ladder with them on and may just opt to take them off in the water and hand them up. (Won't be boat diving with doubles for awhile yet.)

I like the increased sense of stability underwater of the doubles. Less pendulum rolling side to side, slower ascents and easier stops have been positives.
The extra time in shallows if great if your buddy (ies) have similar amounts of gas.
If you are ALWAYS paying attention to time at/and depth, slipping into deco time shouldn't be an issue. I also think that OW classes in the U.S. should include (at least as an option) some deco training. I believe in Europe that is done by some agencies.

I agree that if singles serve you well for the diving you do that's maybe the best choice for now.
My personal situation is that I'm 55yrs. old. Have "intellectual" interest anyway, in deep/deco/ mixed gas diving and wreck exploration, but don't know if I have the stamina, courage, long/short term memory function ;-) left, to know how far I'll go in the Tech. direction. My age makes consideration of all of this a "double edged sword". On one hand, I have a limited time left, (maybe about a decade) physically, to achieve whatever Tech. level I ultimately wish to acheive. On the other hand, I am a relatively new diver and will take things in lengthy "baby steps" not rushing anything. I also must respect my wife's as well as my own tolerance for risk.

If you're (very likely) younger than I am, then there is plenty of time to consider doubles for yourself. I do recommend along with others, to try smaller lighter doubles and do at least a half dozen dives with them before deciding how you like them.

Be certain that you can reach the valves on your manifold with doubles otherwise the redundancy of a 2nd tank doesn't really exist for you.
When I dive a single tank, I always sling a pony for bailout/redundancy.

If you have no interest in deep dives, exploration of wrecks, caves, etc. then
there isn't necessarily a need for them.

Try some LP85s if you can't find the older 72cf.

Good luck!

 

[DivePartner1]

This may be a bit long, but bear with me.

For anyone who wants to go further and get into doubles. I always recomend starting with the old standard aluminum 80's. Why?

Pete Johnson

Thanks, Pete. I'm planning to convert HP100s to double and this is very helpful. I was leaning toward a deco course for the enhanced training and this probably pushes more in that direction.

 

[Gilldiver]

Not a problem and good luck.

FYI - I have 4 sets right now, they are:

1 set 72's these are old steel 72's with original hydro's in the early 70's. They may not be the same tanks as the 72's people are talking about now. I call them my baby bottles and love them for dives between 60 and 110. They are usualy have NITROX 30 or air.

2 sets of aluminum 80's for 110-160. NITROX or mix 20/30
1 set of steel HP 100's for 130-200. Mix 17/35 or 17/50
Any deeper and I will borrow a set -

I have never found a need for twin 125's or some of the other high volume rigs. With the 100's an 80 of 32% and a 40 of 100% you can go just about anywhere you want to go. The exception are the long cave dives, but a cave is someplace I have never had the need to go. There are just too manywrecks out there to go in a hole.

For shallower and 2nd dives to 120 I use a steel 120 with an H valve so that the regs and back plate come off the doubles and right onto the single. The only thing I change between the dives is the BC (a smaller one on the single). This way I can put one set of doubles and the single with the stages (if needed) and do a day without a lot of clutter on the boat.

The bigest problem with all these tanks is doing the yearly vis.
you need to become a tank inspector just to keep from going broke.

Think about the depths and time you will/want to do in the next few years and get what works for you under those conditions. Getting deep or long should be gradual. To do the deep stuff you firstave to have the training and then the experiance. Unfortunatly, the experiance cost a lot - in time and money and fright. You do not know your limits tiil you find them. And when you find them is also the same time you find out what happens when the Sh** hits the fan.

When the 'old divers' get together we tend to BS about how we screwed up and got back. Just about never about the last dive.

Pete