An unmanned, autonomous, ocean-going vessel including a primary hull and a rigid wing rotationally coupled with the primary hull that freely rotates about a rotational axis. At least one of the primary hull and the rigid wing includes at least one selectively floodable compartment configured to selectively flood to submerge the primary hull and at least a portion of the rigid wing. The vessel further includes at least one controller configured to maintain a desired heading. The vessel further includes a control surface element configured to aerodynamically control a wing angle of the rigid wing based on a force exerted by wind on the control surface element. The vessel further includes a rudder. The at least one controller is further configured to determine a rudder position and generate a signal to position the rudder. The vessel further includes a keel coupled with the primary hull.