I would guess your 41 mph GPS is faster than 41 mph speedo in a side by side race. My Johnson is a 60 hp. The boat is an 1989 Supersport, padded rear seat with padded seat backs on the rear bench seat, Bimini top, garage kept Whaler. I am truning about 5700/5800 with just me in the boat to get to 41 mph.
Great boats for kicking around in, I use it one week a year, in Cape May, NJ for our family vacation.
Funny we are talking about 41 mph Boston Whalers in this thread, but that is how fast I have driven a 15' Whaler. Now in the old days a 13' Whaler with a 50 Mercury was the sh*t as a kid.
Here is the Whaler (picture taken four years ago)..my late father driving with his grandchildren on a Cape May, NJ vacation.