The copperhead (Agkistrodon contortrix) is a member of the pit viper family, like most of the venomous snakes in North America. The copperhead (Agkistrodon contortrix) is a member of the pit viper family, like most of the venomous snakes in North America.
The Command Thrust models use the same bigger gearcase housing as the Mercury 150 FourStroke, but with an all-new 2.38:1 ratio ideally suited for pontoons and heavier boats. Itâs the first true oversized gearcase in the industry for outboards in this horsepower range.
1 At forward idle, the Mercuryâs vibration level at the driverâs seat is up to 50% lower than the Yamaha. 2  On the transom, the Yamaha puts out nearly five times more vibration than the Mercury â both at cruise and at full throttle.