As used in this article, “for-hire vessel” includes any vessel propelled by machinery carrying more than three passengers for hire, except the following:
(a) A sea plane on the water.
(b) A watercraft specifically designed to operate on a permanently fixed course, the movement of which is restricted to or guided on such permanently fixed course by means of a mechanical device on a fixed track or arm to which the watercraft is attached or by which the watercraft is controlled, or by means of a mechanical device attached to the watercraft itself.
(Added by Stats. 1963, Ch. 1337.)