Idle speed is defined as the minimum speed that will maintain steerageway, the slowest speed at which it is possible to steer the boat.
Slow speed is boat operation “fully off plane and completely settled in the water.” That’s not very fast. If you’re putting up much of a wake, you’re going too fast.
Normal safe operation is best communicated by the federal definition of safe speed, the speed at which you are able “to take proper and effective action to avoid collision and stop within a distance appropriate to the prevailing conditions.”
All vessels are required to proceed at a safe speed at all times. Maximum speed is not necessarily a safe speed. Safe speed is dependent on factors such as visibility, the amount of vessel traffic, maneuverability of your vessel, wind, currents, local hazards, weather. It requires good and experienced judgment.
If you are involved in a collision, it will be assumed that you have violated the safe speed rule, as you were obviously not able to avoid the collision. Law enforcement personnel can and often do interpret these rules in the strictest manner.