Here's how I get underwater light on my subjects without carrying batteries, cables or expensive strobes to the bottom.
First image shows a normal $250 Princeton LED torch attached to a bubble strobe arm with a galv bolt, white rubber washers and a wingnut through the handle - very stable. Second shot shows the torch attached to the completed project. Third image shows a pearl glass domestic down light sphere with the holes already factory drilled - no drilling or cutting of glass required. Fourth image shows three short shank self tapping galv screws that fit the holes on the glass perfectly. Fifth image shows the screws which screw down into the plastic rim of the torch without peircing any internal parts - no measuring required because all holes line up perfectly with the rubber rim. Sixth image shows the completed torch with diffuser glass plate attached which can be easily removed for more penetrating needs like cave diving and such.
Cost all up - Torch $250 and parts $10AU approximately. Tip: before screwing you can like me drill very fine pilot holes for the screws to relive pressure and help guide the screws into position.
