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Essentially the sub and anchor
combination would still be neutrally buoyant, which means the anchor would rest
on the bottom but have no purchase. In principle this would be equivalent to
simply maintaining depth control by conventional means. If there isn’t a
current, you won’t go anywhere, but if there is a current you’ll go
with it. I must say though that the idea of wanting to go such distances in a PSUB,
ride out storms, etc. sounds daunting, to put it mildly. Rgds, Alec -----Original Message----- I’ve been tossing an idea around for a sub that some may find
useful. It would be nice to get
some input as far as possible “snags” (pun intended) in the design. The sub I intend to build will have to
spend many hours offshore on a single trip in order to get far enough out to
become useful. Inshore water is
near-zero visibility. I’m worried
about seas changing for the worse while out and need a way to submerge to a
“calmer” depth in order to ride-out a storm. To keep from drifting about at 60 fsw or
thereabouts, I was thinking to make my drop weight tetherable (is that a
word?). If things get rough, I plan
to submerge to the desired depth and release a tethered drop weight to the
bottom. Once it hits bottom, the
sub will be buoyant by however much the drop weight weighs and should remain
suspended by the length of cable connected to the drop weight. I am hoping that submerged to a calm
enough depth this will sufficiently anchor the sub in place until such time
that conditions at the surface become more favorable. If this is workable, it would be very
nice for a lot of other things such as compensating for buoyancy changes that
occcur when a diver lockout chamber is flooded, holding divers at 1A for
appropriate “surface intervals” without having to ride a rocking
and rolling surface vessel, etc..
Not to mention that it will keep me very close to my last known GPS
location before submerging and prevent me from drifiting into shipping lanes,
oil platforms, using up battery capacity keeping the sub on station, etc.. My idea is keep the drop weight as
simple and inexpensive as possible, since it may not be easily retracted when
ready (snagged, malfunction, stuck in the bottom, etc.). Of course there would have to be a way
to break it off or at least cut the line.
I had thought I might simply continue unwinding it until the end of the
cable simply slipped from the spool.
The weight would simply be a concrete-filled drum with an eye bolt in
it. The sub would have a similar
shaped cavity in the bottom so that it could be wound up and neatly tucked in
for running. Input appreciated, as always. Best Regards, Cliff |