Sea Perch is probably the easiest way to build your own underwater ROV. It is an evolution from a design featured in the book "Build Your Own Under Water Robot and Other Wet Projects" by Harry Bohm and Vickie Jensen further developed from MIT Sea Grant program. Its design is fully open and it can be constructed easily with simple and cheap materials.---



The basic Sea Perch uses a frame made from PVC pipes. It has two floaters and should be weighted in order to achieve neutral buoyancy. Three waterproofed electric motors can move it in the horizontal plane and also up and down. The small ROV is linked with a cable that is connected to a battery and also a small joystick with four buttons.

You can find all the instructions, parts list and documentation here: http://seaperch.mit.edu/

Hacking and modifying the initial design is highly encouraged and you can find a lot of information on the official website and in other resources.

You can find the original book where the Sea perch was based here: http://www.westcoastwords.com/books

(images: first photo - MIT Sea Perch at flickr, second left - Around the Americas at flickr, second right - MIT )