Originally Posted by
fishingrod
Trying to help a mate who just purchased a 4.74m Seafarer V-Sea (Mk1) that’s fitted with a 2011 60hp Mercury Big Foot 4stroke. Big Foot being the larger gear box with 2.33 ratio.
The current prop (fitted by previous owner) is way too small and the boat is painfully slow. It’s an Mercury SpitFire alloy 4 blade 13.8 x 11 pitch.
From what I can see 13-14” pitch seems more appropriate.
With 2 persons, 40 Litres of fuel, basic safety, but no fishing gear his approximate GPS speeds are :
10 knots @ 4000
11 knots @ 4200
12.5 knots @ 4400
13.3 knots @ 4600
14.0 knots @ 4700
14.5 knots @ 4800
15.5 knots @ 5000
19.5 knots @ 5600
WOT is >5800 with the current prop, but we won’t sure on the max rated engine RPM so didn’t try any harder.
No "foil" is fitted. Whist on the plane the anti-ventilation plate has a “film” of water passing over it, but I would not call it submerged.
Understand that people like SOLAS can provide advice, but hoping to get some recommendations from the Ausfish community on prop size/types/models to consider. With some luck he can find something second hand on Gumtree etc.
I’m hoping we can get him a 17-22 knot cruise in the region of 4000-4600. Achievable ?