Newbie Question

["Sean T. Stevenson" <ststev@uniserve.com>]

I have an idea for a dry two mode sub, to enable diver deployment
without a lock.  Ordinarily operating at 1 atmosphere, the pilot and
diver could conduct a search limited only by fatigue, battery and
scrubber duration.  Once the search object is located, the interior is
blown down to ambient (flushed with appropriate gases according to the
depth), and the diver deployed through a floor hatch.  Once the object
is recovered or sent up via lift bag, the diver returns to the vehicle
and both diver and pilot complete any incurred decompression obligation
inside the vehicle, by maintaining ambient pressure and controlling the
vehicle depth.  This design would make it unnecessary to design for
positive internal pressure, and avoid the associated cost.  I am not
naive enough to think that no one has thought of this before, but would
like to hear comments as to the feasability of this idea.

-Sean