Do you need an oil cooler????
There are several factors to consider. oil pan size, type of boat, primary useage, ETC. these are questions you need to ask yourself.. For a standard run of the mill boat, with a factory type engine you can probably get by without cooling the oil. However, it is just another way to help protect your investment..Also oil coolers are a good way to pre heat the water going into the motor to help maintain a desired temperature.
If you're worried, look for a deal in the future, unless you plan to really wring its neck, you should be ok......Mooneypitt