Re: ambient preference

[Rick Lucertini <empiricus@sprint.ca>]

Alex Wolfe wrote:

>   Greetings all
>
>   As I new member of the list I feel I should introduce myself.  I've
> been toying with the idea of constructing a 1ATM design for almost 10
> years now.  On many occasions (read "revisions") spending months in
> planning only to become frustrated at the cost, bulk, and potential
> safety issues of 1 ATM construction.  I have finally decided that a
> pressure hull is not for me.  Being an avid SCUBA diver, the concept of
> an ambient sub seems much more enticing, almost familiar (a HUGE mask
> covering your whole body 8-) ).  Costs are managable, and you can leave
> the vessel when you arrive at destination.  Bottom time is certainly an
> issue ( I'm a no-deco kind of guy), but I don't see myself spending
> much time below 32 feet anyhow.  Does anyone on this list have any
> experience with open designs (I still like to keep dry though)?  I.E.,
> my big question being are there any pitfalls with ambient designs that
> slipped anyone's mind that I should look out for! :)

Hi, Alex and All . . .

There are a few of us who are partial toward ambient boats for more or less the same
reasons.  I'd like to add that conventional boat building techniques can be used,
whether strip planked, cold moulded, ply covered, cedar strip, fiberglass, etc.

I do like to stay dry.  I dive (well, before the kids came along) in a dry suit.
What I've done is decided to build a cockpit that uses a large ball valve as a flood
and a smaller one as a vent.  Once the mains are flooded, the upper portion of the
canopy would be slightly above the surface.  The lower half of the cockpit would be
isolated from the upper half by a kayaking body sock.  It's just a big waterproof bag
that fits around a cockpit coaming.  The flood would be opened first, then the vent.
As water enters the cockpit, the sock would reduce cockpit volume (should be kept low
to preserve air) by wrapping around the pilot's legs and hips.  The lower body would
still be dry however.

One point is that once the desired buoyancy is reached, both the ball valves would be
closed. The cockpit would now be isolated from ambient water and pressure.
Regulators or pressure differential valves would allow air into the cockpit on
descent.  The cockpit's reduced pressure on descent would provide the partial vacuum
that your mouth otherwise would on the regs.

Rick


--
Rick Lucertini
empiricus@sprint.ca
(Vancouver, Canada)