I can feel the money draining from my bank account at WOT. 5800 RPM = 33.3 GPH = $150/hour at current California marine gas prices. At least I'm moving 45 MPH (1.35 MPG).
At 4300 RPM I burn 14.3 GPH. That pushes my boat at 32 MPH, which works out to 2.2 MPG. Not bad for a 27' boat.