:help:HI I am from Bulgaria and i`m new in RC boat modelling and i need an advise about the build of 32inch Catamaran .I`m using 3mm plywood and for the outer shell i am thinking of using Depron . I am not so good in electronics but i want to make the boat very , very fast .I`m thinking of using brushed motor 550 but there is different types of 550 motors 12T , 22T , etc ... The question is how many T`s the motor have to be and  what will be the best ESC for this type of motor? What type of electric motors do you use for speed boats?

Nice workmanship! 

Depron for the outer skin doesn't seem a good idea. It is weak (a small collision can result in a tear or hole) and brittle. Also, if you try to fiberglass it the resin could eat into it

Better use 3 mm balsa strips

If you want it really fast use a brushless outrunner or inrunner, water cooled

eg  https://hobbyking.com/en_us/turnigy-xk2845-3650kv-brushless-inrunner.html

with   https://hobbyking.com/en_us/turnigy-rc-boat-esc-70a.html