After making a camera which was very water tight but too large, we made a smaller one for 2003. But the initial design had lithium batteries inside – but we switched to a 12V power cable so we could seal the unit completely.! So we added 75m of mains wire with 12V from a lead acid battery on the top, sealed the inside with potting compound and silicone sealant and it worked extremely well! A monochrome CCD with six infra-red leds was used. The leds did not really provide enough light. A maglite torch hanging underneath was very good too – but the reflection off the back was annoying. The signal was plugged into a DV camcorder with composite input – so many hours were spent looking into the eyepiece.