Next on the list of factors is pressure. When you increase the surrounding pressure, you can usually dissolve more gases in the liquid. Think about your soda can. It is able to keep the fizz inside, because the contents of the can are under higher pressure.
Assuming a prop, it depends on how you are propped but with a redline of 6000 rpm, most outboards perform best with a cruise in the 4000-4400 rpm range. If you want top fuel economy, get a floscan or such and see what is the most efficient for your engine and prop.
SPECIFICATIONS FOR 115-HP FOUR STROKE OUTBOARD MOTOR. GENERAL. The overall scope of these specifications is to describe a 115-HP, 4-stoke direct fuel injection, outboard motor. All motors bid shall be the latest manufacturerâs production model and meet or exceed all USCG, State, Federal, OSHA and ANSI regulations for this type of equipment that are in force at the time of delivery.