30inch catamaran , 1800kv want to get over 50mph on 4s if possible. Thinking of an m445 for its increased rpm or an m645 ,

Opinions? Temperature wise I hope it will be alright , I got 2 water pickups one is split for esc and motor mount and one goes right to the motor directly all with 1/4 tubing. If not then Maybe x445 or something like that.

Thanks for your help