5. For the purposes of this Schedule —
(a)a ship’s tonnage shall be its net or register tonnage (as the case may be) entered in its certificate of tonnage issued by or on behalf of the administration of the State of Registry; or in the case of an unregistered ship or a ship measured only by length the tonnage reckoned in accordance with the Thames Measurement adopted by Lloyds Register;
(b)a year shall be reckoned from 1st April; a month means a calendar month;
(c)in calculating any payment of light dues where the ship’s tonnage is not a multiple of one ton any excess not exceeding half a ton shall be rounded down and any excess over half a ton shall be rounded up to the nearest ton;
(d)“length” in relation to a fishing vessel or a tug means the registered length shown in the ship’s certificate of registry and in relation to such a ship having no registered length, means the length which would be the registered length if the ship were registered under Part I of the Merchant Shipping Act 1894 or Part II of the Merchant Shipping Act 1988(1), provided that in calculating any payment of light dues where a fishing vessel’s or a tug’s length is not a multiple of one metre, any excess not exceeding half a metre shall be rounded down and any excess over half a metre shall be rounded up to the nearest such metre except in the case of a ship with a length of less than 10 metres;
(e)“registered fishing vessel” means any fishing vessel registered under Part II of the Merchant Shipping Act 1988 or registered as a fishing vessel under the law of some other country;
(f)“Ro/Ro ferry” means a ship—
(i)provided with cargo or road or rail vehicle spaces extending to either a substantial length or the entire length of the ship in which vehicles or cargo can be loaded or unloaded normally in a horizontal direction; and
(ii)which operates on regular advertised services available to accompanied motor vehicles or unaccompanied trailers on payment of an advertised fare or similar tariff charge.
(g)“pleasure craft” includes a pleasure yacht and means a vessel used for sport or private recreation and not engaged in any revenue earning or commercial activity or service.