English term (edited): operate the engine in gear

"The engine in gear" refers to the state of the engine when it is actively engaged with the transmission to deliver power to the drivetrain, propelling the vehicle (in this case, a boat) forward or backward. When an engine is "in gear," it means it is not in neutral or idle; the transmission is set to a specific gear ratio that allows the engine's power to be used for movement. The directive to "operate the engine in gear" suggests that the engine should be running and actively driving the boat, rather than idling or being tested without load. This is a crucial detail for the context, which seems to be about a break-in procedure or specific operational guidelines, indicating that the boat should be moving under the engine's power within the prescribed RPM or throttle limits to ensure proper engine conditioning or to meet certain operational criteria.