Bit reluctant to post this, since this boat is made of a 3D printed hull, the RIBs are made of insulation tubes, the electronics are all RC parts and the motor is a brushless drone motor.
NEVERTHELESS ..... It looks like a LEGO boat, don't you think?! And it works great!
Happy to share more details if there is interest, happy to remove it, if it's too little LEGO for the forum.