flymo wrote:For prop selection, your friend will want to do some homework.
First go to Boston Whaler's website and review the performance reports for that hull, and make an estimate of what top speed you'll be able to achieve. Then use the Prop Calculator linked at the top of this forum in the announcements section - enter in speed, RPM, gear ratio, and a guess at slip (I'd be inclined to use 0 for starters, assuming you're going to use a modern stainless steel prop) and then the calculator will give you the pitch.
From the looks of the hull, the boat was left in the water without being bottom painted, so there's likely some water intrusion and possibly some gelcoat blistering, both of which will affect top speed, so your friend may want to adjust for that.
Without trying to start a whole discussion on overpowering, it's my opinion that the BW 13s and 15s are sadly underpowered, with a maximum power rating designed to sell Mercury motors rather than perform decently. So depending how your friend feels about it, one could explore putting more motor on there—the E-TEC 40, 50, and 60 all weigh the same. This could be particularly important if the hull has a lot of water in it.
Good luck.
Thanks for the feedback flymo.
Yes, I can do the calculations and homework with the prop slip calculator and then test props, but thought there may be someone here that's already performed this exercise. This will probably get an aluminum prop since it may also be used in the shallows and aluminum is easier on the gearcase internals if a rock is encountered.
Boat was a freshwater boat and has a hull stain, probably from the iron content in the water or something else. The hull is dry and does not have any hint of osmotic blistering. It will be barrier coated and bottom painted for the saltwater and spend summers on a mooring.
D-