Camera for use at Vortex

[SC_Hoaty]

This is a thread to discuss hypothetical camera systems for use in the Vortex Springs cave system to search for additional information regarding a missing diver. Threads about the missing diver are in A&I, while some information about Vortex is in the Cave Diving area. In an effort to keep the speculation and hypotheticals in their appropriate pidgeon holes, this thread has been created.

Rough Statement of the Problem

1) Underwater environment
2) Flowing water (desire to go "upstream" against the flow)
3) No natural lighting (Cave)
4) 120 160 FFW (this needs to be corrected - I think this is close, but I'm going by memory)
5) numerous tight passages (difficult for human access)

Potential Solutions
1) Power
a)Tether
b) Battery
c) other? (generate from flowing water?)
2) Data
a) record (tape, solid-state, ...)
b) Transmit via cable/tether
c) Other?
3) Lights
a) supplied by power source in #1 above
b) alternate power source?
4)Propultion
a) self-propelled
b) diver propelled
c) other?



One Concept -
Tethered system. Diver Deployed. Divers carry a reel with the tether, and advance it through the cave system. This laying of the tether is similar to laying a line in a cave, and should use familiar skills. This eliminates tether drag and snag. Power for lights and camera is in the tether, along with data transmission to bring video to surface. The camera/lights can be attached to a pole for manual deployment into tight restrictions. The system can be advanced by teams, since it can remain in the cave system indefinately. (Bulb life may be an issue, and perhaps lighting power is switched off from the surface until desired to extend bulb life).

Other concepts and their pros and cons are desired - that's the point of the tread. Feedback from cave divers is particularly desired.

Thanks!

[SC_Hoaty]

The last few hundred feet of lined cave there is incredibly tight and silty, so it'd have to be able to be pushed several hundred feet with twists, turns, ups and downs if a cave diver is going to have to manipulate it(and I suppose see whats actually going on in front of it)...

...and you'd still need a camera + housing rated for 160' that is small enough to push through the restrictions.

And a battery pack + lights, which are heavy, so that limits how far you can stick that pole...

OK- Good stuff. Add local monitor on tether reel or someplace for diver to see what camera sees, in addition to it going up to the surface. Need to change depth to 160'. Need bouyancy system for heavy items.

Also, maybe have batteries near camera for power "in use" and trickle charge through tether during down time. This may require hydrogen gas management from battery charging.

[SC_Hoaty]

Kinda feel like I'm talkin' to myself here!

More criteria - tether length should be around 2000 feet.

The issue of stirring up muck and needing to wait for it to settle leads me to think that a camera of the type described (tethered, diver deployed, able to survive long periods submerged) may be useful for other cave explorations as well. The ability to move it near where you want it, and then use it days later (when viz is better) might have other cave applications.

Will the video need amplification to send it 2000 feet?
What voltage loss along the tether is to be expected during trickle charging?

More details to be defined.