There are several other issues to consider when comparing
the small PSUB vs. large PSUB that are not often discussed:
1. Reserve Buoyancy ? Smaller submersibles have an
exponentially smaller reserve buoyancy in case of an emergency. What
might be a minor leak in a large submersible can be catastrophic in a small
sub as it will take a smaller mass to adversely affect
buoyancy.
2. Ease of Repairs ? As Carsten noted, it is much easier
to craft a large PSUB with plenty of room to work. In case of an
emergency, this makes it possible to accomplish repairs while underwater.
In the smallest PSUBs this is impossible and you might not be able to
surface.
3. Probability of Escape ? There are two points
here:
a. Moderate flooding in a larger hull allows time for
thought about how to go about your escape as every emergency is
different. Minor flooding in the smaller subs that have the operator
prone or semi-prone can quickly lead to incapacitation of the
operator.
b. The smaller PSUBs are very cramped and do not allow
much room to move around inside and will be difficult to egress from in an
emergency. Body form-fitting small PSUBs should be considered for the
building of an escape simulator to work out and practice emergency egress
under a variety of conditions. The largest PSUBs are multiple
compartmented and facilitate isolating the leak to a compartment while
escaping to another. Moderate sized submersibles may provide sufficient
room if properly designed to allow a successful escape of a single operator;
multi-passenger moderate sized PSUBs require much more design, thought, and
practice for successful egress of all personnel.
Carsten makes some good points for both large and small
PSUBs. While I would love to build a big PSUB, practicality of my
situation (and probably most PSUBERS) dictates the moderate sized personal
submersible.
R/Jay
Respectfully,
Jay K.
Jeffries
Andros Is.,
Bahamas
A skimmer afloat
is but a submarine, so poorly built it will not
plunge.