Re: The " build a sub for under $500" plans rip off

[Ben Trumble <trumble@well.com>]

The popular-links boat is essentially a recycled idea from a mid-70's
design that appeared in Popular Science (or maybe Mechanics...) The plans
are ridiculously simplistic, and overwhelming in their lack of technical
detail.  It is, I should note however, a viable semi-dry sub.  The problem
is that it's a also a death trap, since the "Bubble" closes and fastens
from the outside, making an emergency exit almost impossible.  Better
semi-dry designs are always open at the bottom of the boat.  The bouyancy
control in the p-links boat is identical to the earlier mid-70's design.  I
tried using it in the semi-dry sub I built in Honduras 12 years ago and I
had nothing but problems.  Bouyancy really needs to be maintained
automatically.

Ben


>Hey guys - I succumbed to purchasing plans on "building your own
>submersible for under $500.00" from the popular-link deal on the internet.
>for about $20 they sent me ten xeroxed pages with instructions like" lay
>fiberglass sheeting into the form of a submarine, then put in you air tank,
>they your off..." It included some relatively useless sketches of the sub
>you could build if you had a degreee in fiberglass technology.
>At any rate, if anyone is interested in seeing them, I would be happy to
>mail them the original version ( cant I get in trouble for copying it? ).
>I would just ask that whoever wants them, make it available to the next guy
>after you see how truly worthless they are.
>They use a pice of pvc pipe with an elbow joint to let the air out of the
>trapped bubble of the wet sub.  Pointing it so the pipe is up, lets air out
>and you sink. Pointing the pipe down, the tip goes below the water line
>and you stop descending.  A scuba tank provides more air as needed.
>at any rate - e -mail me if you are interested.
>
>Thanks,
>
>Greg


"I never met a rattlesnake I didn't like."