Cooling can to modify the Castle Creations 6th scale Mamba Monster X 8S ESC for boating use.  These water proof speed controls are good up to 300 amps in FE boats!  Compact size that packages well in any boat.  To modify yourself, just remove fan and shroud with 1.5mm Allen wrench.  Break off all perimeter cooling fins as shown in photo.  Mill or grind the removed fin stubs.  Glue on your cooling can with JB weld epoxy.   You get cooling can with pre installed water nipples.  6061 T6 aluminum CNC machined part with 10x32x8th in nipples installed.