I make something for use in swimming pools out of plastic plumbing pipe, but
a fellow I was talking to last night had a more demanding use; design
suggestions, and perhaps pointers/offers to manufacture would be
appropriate.

This fellow needs to have video camera underwater, salt water, on device
that is moored to the bottom on cables. The device is mobile, and the
maximum depth is around 30 metres, with a video cable run of about 100
metres. Currents range up to about 10 knots. There could be a bit of
turbulence, rocks, and general knocking about.

Off the top of my head I was thinking that a small surveillance-type camera
with a flood light and some sort of video amplifier, all mouted in a small a
stainless steel tube as possible, caps and an end window for the camera &
light.



30 metres depth is about 100 psi, so sealing will be an issue, but this
should just be proper design and workmanship, not innovation.

100 metres of a video run seems like a long way, and as well I do not know
if the video cable will be exposed to salt water; probably not, but the
possibility should not be ignored.

Mounting the device: would welded ears on the tube be likely to fail given
the environment, materials, and forces? Or would it be better to have some
sort of clamp to grab the tube?



There seems to be a need for more than one of these, and although I guessed
a figure of $1000 for a cheap proof-of-concept unit, the fellow didn't
seemed worried about sums in that range.