Re: [PSUBS-MAILIST] Alternative hull material.

[Ward Monroe <wardomon@minn.net>]

Yes exactly, a "snorkel sub".  The ideal solution to the shallow,
sometimes murky lakes we have here in Minnesota.  The Riley sub is cool
enough, but a maximum depth of 40 inches seems rather limited.  I've
figured out a way to safely place the "sub" part at about 8 feet without
significantly increasing the size of the craft overall. That puts it
outside of the weed line in most of the lakes around here.  Perfect for
scoping out the hot fishing spots.  Mounting a  couple of lights would
make 20 feet of water about perfect for night dives...  a compressor to
keep the air tanks topped up... BottomLine (brand) sidefinding sonar...
winch and grappling hook for salvage use... GPS...

Like I said, I've been thinking about this for over 20 years...     


On Tue, 2003-03-18 at 11:33, Warren Greenway wrote:
> Have you considered a partial-submersible? There are
> those designs that have pontoons that stay on the 
> surface, and in that way limit the depth. It isn't a
> real submersible, but it would be safer, easier to
> make, and will let you see the under-water sights.
> Also,
> this type of sub would really lend itself to
> fiberglass.
> 
> Warren.
> 
> --- Ward Monroe <wardomon@minn.net> wrote:
> > Thanks for the clarification.  My bad.  I should
> > have said "1 atmosphere
> > over ambient" to be more precise.  As a kid I used
> > to free dive with
> > mask and fins to 10 feet all the time.  It's a
> > pretty good squeeze, but
> > not a real problem.  I would think that the
> > strength, formability,
> > durability, life span and hydrophobic qualities of
> > fiberglass would be a
> > safe material for the rather benign conditions at 8
> > feet.  And surely
> > catastrophic compressive failure would not be an
> > issue for a properly
> > constructed shape.  Seeing as weight is good, an
> > overly thick hull
> > should easily handle the stresses.
> > 
> > Thanks for everyones comments.  Back to lurking...  
> > 
> > On Mon, 2003-03-17 at 06:06, peter mckellar wrote:
> > > Hi Ward,
> > > 
> > > >Please correct me if I'm wrong, but isn't 33 feet
> > 1 atmosphere?  The
> > > pressure at 8 feet is almost trivial. 
> > > 
> > > 0'  = 1 ATM
> > > 1 ATM = 14.7 psi
> > > 33' = 2 ATM (2 ATM is actually 32.8')
> > > 8'  = 2.5m
> > >     = 1.25 ATM
> > >     = 18.4 psi (true, pretty trivial)
> > > 
> > > i've rounded a little in the sums :)
> > > 
> > > 14.7 psi seems higher than my faded pre-metric
> > memories suggest.  can anyone confirm this is
> > correct?
> > > 
> > > the conversions were done by:
> > > 
> > >   http://www.megaconverter.com/Mega2/
> > > 
> > > 
> > > hope this helps
> > > peter
> > 
> > 
> 
> 
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