The correct answer is C) The bow will swing to the left, straighten out and then swing to the right as the vessel loses way. This is correct because when a right-handed single-screw vessel with headway on has the engine put full astern and the rudder hard left, the bow will initially swing to the left due to the combined effect of the reverse thrust from the propeller and the rudder being hard over. As the vessel loses way, the bow will then straighten out and eventually swing to the right as the vessel loses momentum. The other options are incorrect because: A) The bow will not swing to the right, as the reverse thrust and rudder hard left will cause the bow to swing to the left. B) The bow will not just swing to the left without increasing or decreasing its swing, as the vessel will lose way and the bow's movement will change. D) The bow will not continue to swing left faster as the vessel loses way, as it will eventually straighten out and then swing to the right.