An auto reel and a thin Kevlar line might
work. I gave up on the idea mostly because most of my sub diving is in man-made
lakes that are full of trees. Instead of adding to the comfort level it was
another thing to worry about. These days I really think that a good OTS style comm
system and a buoy that can be released in an emergency is the best way to go.
The other thing that is really important
is that if your safety plan includes a support diver topside that the
conditions are not going to require a level of skill that is too much for them.
Too deep, black water, frigid temps and fear can easily turn one emergency into
two. Try to take time to go over every possible scenario for each location and
discuss the emergency plan in detail with the whole crew before going down.
Safety means more fun!
Greg
From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Recon1st@aol.com
Sent: Tuesday, August 04, 2009
1:04 PM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] towed
antenna
Greg thanks for the
info. These are exactly what I had anticipated as the problems. I have
just
about all but given up
on the idea. I may play around with trying to spool the tether from
the buoy, with some sort
of auto reel.
Do you think it is
possible to pull one at 100ft with a very thin diameter tether?
In a message dated 8/4/2009 10:24:02 A.M.
Central Daylight Time, greg@precisionplastics.com writes:
The depth was 40ft and the tether was regular 70ohm antenna cable.
I was also using it for communication. The problems I encountered were that the
cable sinks and gets wrapped around everything. My next version had small
floats every 6ft but it they got tangled around stuff. My next try was to run
the cable through a number of 8’ lengths of 3/8” PVC pipes with
foam pipe insulation for flotation. This actually worked pretty good- it never
tangled and as the sub descended it would take down the lengths of floating
plastic pipe 1 at a time. Surface support could tell my depth by the number of
pipes on the surface. But it was very bulky since it couldn’t be rolled
up and a real pain to haul around.
A towed tether would probably be ok if it were a line that float
(instead of comm. cable) with a spring loaded release/ take up reel, but I
still wouldn’t drag a long piece behind a sub unless there were also a
dependable means of getting away from it if it got tangled (like a tool that
could cut the line from inside the hull).
Greg
From:
owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On
Behalf Of Recon1st@aol.com
Sent: Tuesday, August 04, 2009
10:22 AM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] towed
antenna
Greg How deep were you able to pull the buoy, and what diameter of
tether did you use?
In a message dated 8/4/2009 8:17:29 A.M. Central Daylight Time,
greg@precisionplastics.com writes:
A long time ago, I used to trail an antenna and buoy on the surface
but found this to be a real hassle- I like the releasable type that Alec has
much better- that’s my next upgrade.