[SpaceShipOne] has built this very nice looking under water ROV.  It is still a work in progress, but nearly complete.  This ROV is a fairly simple construction. most of the body parts are held together using zip ties.  There’s no microcontroller and no custom boards.  He’s using a radio control transceiver that was intended for airplanes to control some standard speed controllers and servos.  For thrust, he pulled the motors out of some bilge pumps and fitted them with propellers.  He’s only tested it once, but promises videos from the lake soon.  He mentions [Jason Rollette] several times since [Jason] has done both simple and complex designs in the past.