Blowing an esc means the motor is drawing more amps than the esc can handle...
What type of brushless motor is it? In runner or out runner?
Also what size prop are you using...?
If your using an inrunner type motor ( they look like a standard brushed 540 motor) then you will blow esc’s regardless as they are high rpm designed for sub surface props or aircraft use with only air resistance and pretty useless in tug boats..
If it’s an inrunner swap out the motor for an outrunner if still wanting to keep brushless, if not you need a big brushed motor like the mobile marine models t12 or a mfa 850-900 with matching 30-40 amp esc.
We need more details but this above should help you a little.
I’ve never added a brushless motor to a model tug and never will for the reason they are heavy models they sit low and generally have large props and a brushless motor will alway and struggle.
Modern is not always the answer.
Anyway get back to us on model details I’ve mentioned and I’ll see what other helpful info I can add.
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