This is no swamp buggy!  It's a fanboat with style!   It is also a free download.  This is a planing hull designed to utilize  high kv counter rotating drone motors as as fan propulsion.  Our Test boat used twin Mamba 1408 kv racing Drone motors found on a Diatone GT 349.  Why?  Because we had spares, and also we discovered that only a single motor would flip the boat over from the torque.  Fortunately, brushless motors can still run underwater.  Who knew......  Saved me from a December swim.
 
Specifications:
length: 496.35 mm.
width: 143.34 mm.
See the printing and assembly instructions here.
Motors: 1408 400 kv brushless motors.
esc (2) Brushless esc 40 amp rating.
Battery:  3 cell 2200 Mah.
servos:  (1) micro 
Largest build volume required:
Main hull:  143.34 x 102 x 368 mm.