But how do I go from web cam to ethernet? I found this on amazon http://www.amazon.com/SANOXY-over-Extension-Cable-Adapter/dp/B003BDMK3S/ref=sr_1_1?s=electronics&ie=UTF8&qid=1344427592&sr=1-1&keywords=ethernet+webcam, can I use someting like that? What if I use a 300 ft ( nearly 100 meters) CAT 5 cable instead of only 150 ft?
Serial comunication cables can reach 50 meters and to reach more than a hundred you need some ICs like a couple of max483. The real problem is with the web cam signal, I need to see what's happening in real time and to see it on a screen. Usb cable can't reach more than 5 meters... What happens If the cable is more than that? Is there any solution?
otherwise, the suggestion of a Ethernet camera would work, though they are more expensive and heavier.
considering the pressure at 300 feet (just short of 150 psi), the cost should be more to build the submersible hull with a non-leaking viewport and connectors. Just a thought...
how do I chose to use a RS422? When I connect two arduino with pin 1, pin0 and ground is it using RS232? I'm not really practical of these things..