Basic hull design 300mm long, prints in three pieces. The pumps are printed assembled and glued together with acetone. Final mounting is up to you but I chose to use a clamp style mount on the end and seal around the intake and output with hot glue. The boat can also be used with any type of RC boat propulsion on the market of the appropriate size. Boat hull bottom will be coated in marine epoxy, primer, paint, and clear coat to make it stronger. Impellers are designed to be press fit and glued to a 3mm axle with 3mmID 6mm OD bearings and a 3mm ID 6mmOD rubber groment to keep water out. Then with a 30mm pulley at a right angle to a 10mm pulley on the drive motor which will drive both pumps. The Pilot hole on top of each pump is for a water nipple to be added at a later date for water cooling to the motor, esc, and battery. Update 4/21/14: I apologize to everyone who has been making this that the top files were incomplete. I have added the last file (Top2.stl) and will be posting pictures of my build soon. Weather is starting to get nicer here so might be able to even get some action vid as soon as I can get to the lake. Update 11/6/13: I ditched the belt drive pumps because there was to much draw on one motor and the belts were hard to keep on the pulleys at high speeds. I designed a direct drive version which uses a 34mm bolt pattern standard with most 28mm brushless outrunner mounting plates. The shaft of the outrunners was removed and a brass one inserted to help with cooling and provide a longer shaft to reach the impellers. Also added a 3 piece top design to the boat which was glued on and a cover will be made at a later date. 10/25/11 revised my pump design to use a 3mm shaft with a 'D' milled in each end for the pulley and impeller to grab into. At full throttle the belts fell off the pulleys and after adding an idler point and making the main 30mm pulley bigger the problem was solved. Updated Revised pump.zip with up to date pump design.