Deleted (Posted on wrong topic).

I would go with 540 or 550 motors. Try them out. If you need more power, swap them out.

Just got in and catching up on emails. Apologies bruced, unable to offer any advice. However I'm sure the good members on this site will be able to help. I've just seen and read Alessandro's post 👍

Hi Bruced.

I'm the least suitable person to give you advice on this, in fact in another topic I'm trying to get an idea of how to proportion the propellers to the model and the motor to the propellers.
It's a fun exercise, and if it's also useful, even better.
The Link is at the end.
Since you haven't had any answers so far, I'll try to help you in some way.

I would start from the dimensions of the propellers based on the length and weight (displacement) of the model.
Once the diameter of the propeller was established I would choose the motors.

Tell me how much your boat weighs.

Do you already know the type of propellers you are going to fit?
The diameter is mainly of interest but if you want you can add other information (number of blades, material used, pitch, etc. etc.)

In the next post I will try to collect some more detailed information and some examples.

forum/135377

How do I determine motor size, and battery, for my coast guard MLB 47' ? It's 36.5 inches long, deep "V" , Dual prop. I Don't have the plans or instructions. It was one of " Coast Guard Models" kits 1:16 scale.