Mini Dub's (shore diving)

[Scubabill]

Hello all,


I have decided to again start doing some shore dives from the coast of S. Florida.
(soon) I have been reading allot of threads about pony's, Spare Air, sling mounts, ect ect. I think what i want to do is build me a ultralight, easy to handle, double's, solo shore diving rig. I couldn't think of a better place then here, to help me (and others) configure the ultimate solo diving, shore rig. My self imposed limits on this rig will be (@ solo)50ft depth max. Anything deeper then that, im diving with a buddy, and different rig. So when we talk about this kit, lets please keep in mind those restrictions, no need to spend hours talking about diving it solo to 100ft ect ect.
I'm looking for something ultra light, twin tanks, BP/W, Ultra streamline, and minimalist.
I have a good friend that works on water jets, and cnc. He will fabricate some of the metal items needed for this kit.

So lets get started, on helping me build the safest (as we can) ultra light, solo shore diving, kit ever made!

Here is what im thinking so far.

Duel 45 +/- tanks steel, light as i can buy them, painted in epoxy paint.
carbon fiber tank rings (made by me) pre preg
Harness with one clip on shoulder (easy to get out of, remember 50ft max)
tanks run separate of each other, first tank will only be run down to 500psi MAX, then to be used
for redundancy, if problem with 2nd tank after switch over.
Sealed 1st stage's
The best anti free flow type 2nds we can use. (not as prone to free flow)
Im thinking mk17-250v's


So lets talk about hose routing
1st stage mounting
what tanks to use, for most benefit, safety, Proper trim.
What type of weight system should be used
Any ideas that you feel would improve this kit, and make it the best rig ever assembled
for the task of fairly shallow shore diving solo.
As safe as we can design it.



I hope everything remains civil, and people enjoy this thread, with as little flaming,
as possible. This item is of great interest to me.


Thanks.

 

[Scubabill]

Here is what i got so far........

Pre Preg carbon fiber back plate. Molded to ones back. Custom fit
Carbon fiber duel tank rings/mounting to back plate
All 'pluming' in Titanium or ultra light Aluminum.
Ti bolts
HP steel tanks (trying to get around 90 with two on a good fill) Light as can be found
Under 45# ready to dive (i edited this, had 30lbs, that was not possible, after looking at tank weights)




Question: Would it be possible with compact tanks to run them on your back upside down, so the valves
where easy to reach, right off your hips?

ADDED: I think i found a good tank for doubles. Tell me what you think.....

OMS 45
LP 2640 +
23"
5.5" Dia.
18lbs each.
-2,72 full
+.57 empty

 

[Jimmer]

Those are perfect tanks for mini dubs. I have a set of them on an isolation manifold with bands, and those are my go to tank for shallow soloing. They just balance so nice in the water. I use mine right side up, as I would with my big doubles as well. But I would see nothing wrong with mounting them upside down if it works for you.

 

[giles45shop]

I would pick Apeks regs XTX 50/DS4 or TEC3's, but that's my preferred brand. I would also re-look at your design criteria. You are diving salt water, if you don't figure your total buoyancy (you, exposure protection, tanks, etc.) starting out, you may end up with an ultra cool, ultra high $ set up and 10#'s of lead on a weight belt to get you to sink.

There is no such thing as titanium or aluminum "plumbing", and again, no need. You are talking about a non-isolated set-up, so there's no cross-over manifold. It's just hoses. get Milflex if you want to have flexibility and light weight.

This is an interesting excercise, but not really practical or necessary for your given conditions. As with any engineering design, cost should be a factor as well. You want the lightest and best of everything, but can you really afford it?

For the diving you describe, my design would be a single AL80, BPW w/ a comfort style harness. I suspect it will be just as light as the over-engineered doubles rig and WAY less expensive and complex. For the couple breaths of air to get you from 50' to the surface in an emergency, a Spare Air would be sufficient if you really needed it. You are not likely going into NDL limits on 80-90 cf of gas at 50', so a 3 min safety stop is not a requirement in an emergency (my opinion).

Not trying to flame here, just looking at praticality.

John

 

[DaleC]

Try reading this thread (or didn't you like the answers you got there?) http://www.scubaboard.com/forums/basic-scuba-discussions/293635-small-doubles-kit.html