[Putershark]

That speed can vary greatly pending on prop pitch and type, boat load, trim, water conditions, etc, etc... Cruise speed though is not top end speed.

What most are looking to secure is the greatest range (even more important at $2.50 plus a gallon fuel) and most engines are designed to return such right at the 3000 to 4000 RPM mark. Any slower and you can loose MPG and much faster will greatly increase fuel burn (double or more GPH) for not a whole lot more speed.

WOT RPM measurements though are use to make sure that the engine is propped correct with that hull (here again that is not always constant) since the prop is also used as a way to govern / regulate the engine RPM.

This method of engine governing though is not as important today as in the past since most all modern 2 and 4 stroke engines are "limited" (over-speed protection) as to max permitted RPM's by the ECU. The ECU will start shutting down fuel to injectors if the engine starts to over-rev where as in the past, the prop (or the engine blowing up ) was the only real way to do such

Though having a boat propped to return the best top end speed is the goal of most, I look to also try and secure the best cruise speed when the engine is running right at 3000 RPM. Even if you loose a knot or 2 of flat out speed, you may be surprised as to how much faster it gets on a plane, has extended range and just how slow the engine can run and still keep the hull on a plane. Fuel flow gauges are excellent tools to find the "sweet spot" that your engine likes to run at that give you the greatest range, but if you don't such a tool... Best speed at 3000 RPM makes for a great starting point all things being equal.