An inboard-powered boat lacks the directional thrust of steerable drivelines, like outboards, sterndrives, water jets and pods. Instead of a steerable prop or nozzle, they rely on deflection of the propeller stream by a rudder. Compounding things, when in reverse, there is no stream of water from the prop flowing over the rudder at all. This couples with a propeller’s tendency to induce a sideways motion to the boat that kicks the transom to the side. Thus, when trying to go astern, the uninitiated skipper can suddenly find the boat going in circles. Even shifting into reverse to slow down may cause the boat to go sideways enough that all it takes is an errant gust of wind to put the boat at the mercy of the elements.