I am doing a project for school with an underwater ROV. We've wired it with a camera so that on the other end it has a RCA cable. I have a portable DVD play and all the specs are at this radio shack web site.
http://www.radioshack.com/product/index.jsp?productId=3100848&tab=summary
But were are looking for some way that we can record a live video feed from the dvd player. But i also have a RCA splitter so i can hook it to the recording device. But i am having trouble figuring out what kind of device we can use. Whether it is a camera or recording device, but it can't be anything that requires to be constantly plugged in. because we go on boats and everything so, it would be better if it was battery operated.

Thank you for your time and help