The correct answer is "the boat who is not overtaking the other or the stand-on vessel".
In seas navigation, collision regulations state that Give-Way vessel is the one who overtakes the Stand-On vessel. The Give-Way vessel is the one who is taking the replacing operator of the Stand-On vessel. In order to avoid a collision the Give-Way must take early action to pave way for the Stand-On vessel who navigates at a constant speed.