Regulation 49 - Seasonal Tropical Areas
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Regulation 49 - Seasonal Tropical Areas

 The following are Seasonal Tropical Areas:

  (1) In the North Atlantic

An area bounded-

on the north by the rhumb line from Cape Catoche, Yucatan, to Cape San Antonio, Cuba, the north coast of Cuba to latitude 20°N and thence the parallel of latitude 20°N to longitude 20°W;

on the west by the coast of the American continent;

on the south and east by the northern boundary of the Tropical Zone.

  • Seasonal periods:

    TROPICAL: 1 November to 15 July

    SUMMER: 16 July to 31 October

  (2) In the Arabian Sea

An area bounded-

on the west by the coast of Africa, the meridian of longitude 45°E in the Gulf of Aden, the coast of South Arabia and the meridian of longitude 59°E in the Gulf of Oman;

on the north and east by the coasts of Pakistan and India;

on the south by the northern boundary of the Tropical Zone.

  • Seasonal periods:

    TROPICAL: 1 September to 31 May

    SUMMER: 1 June to 31 August

  (3) In the Bay of Bengal

The Bay of Bengal north of the northern boundary of the Tropical Zone.

  • Seasonal periods:

    TROPICAL: 1 December to 30 April

    SUMMER: 1 May to 30 November

  (4) In the South Indian Ocean

  • (a) An area bounded-

    on the north and west by the southern boundary of the Tropical Zone and the east coast of Madagascar;

    on the south by the parallel of latitude 20°S;

    on the east by the rhumb line from the point latitude 20°S, longitude 50°E, to the point latitude 15°S, longitude 51°30'E, and thence by the meridian of longitude 51°30'E to latitude 10°S

    • Seasonal periods:

      TROPICAL: 1 April to 30 November

      SUMMER: 1 December to 31 March

  • (b) An area bounded-

    on the north by the southern boundary of the Tropical Zone;

    on the east by the coast of Australia;

    on the south by the parallel of latitude 15°S from longitude 51°30'E, to longitude 120°E and thence the meridian of longitude 120°E to the coast of Australia;

    on the west by the meridian of longitude 51°30'E.

    • Seasonal periods:

      TROPICAL: 1 May to 30 November

      SUMMER: 1 December to 30 April

  (5) In the China Sea

An area bounded-

on the west and north by the coasts of Viet-Nam and China from latitude 10°N to Hong Kong;

on the east by the rhumb line from Hong Kong to the Port of Sual (Luzon Island) and the west coasts of the Islands of Luzon, Samar and Leyte to latitude 10°N;

on the south by the parallel of latitude 10°N.

Hong Kong and Sual are to be considered as being on the boundary of the Seasonal Tropical Area and Summer Zone.

  • Seasonal periods:

    TROPICAL: 21 January to 30 April

    SUMMER: 1 May to 20 January

  (6) In the North Pacific

  • (a) An area bounded-

    on the north by the parallel of latitude 25°N;

    on the west by the meridian of longitude 160°E;

    on the south by the parallel of latitude 13°N;

    on the east by the meridian of longitude 130°W.

    • Seasonal periods:

      TROPICAL: 1 April to 31 October

      SUMMER: 1 November to 31 March

  • (b) An area bounded-

    on the north and east by the west coast of the American continent;

    on the west by the meridian of longitude 123°W from the coast of the American continent to latitude 33°N and by the rhumb line from the point latitude 33°N, longitude 123°W, to the point latitude 13°N, longitude 105°W;

    on the south by the parallel of latitude 13°N.

    • Seasonal periods:

      TROPICAL: 1 March to 30 June and 1 November to 30 November

      SUMMER: 1 July to 31 October and 1 December to 28/29 February

  (7) In the South Pacific

  • (a) The Gulf of Carpentaria south of latitude 11°S.

    • Seasonal periods:

      TROPICAL: 1 April to 30 November

      SUMMER: 1 December to 31 March

  • (b) An area bounded-

    on the north and east by the southern boundary of the Tropical Zone;

    on the south by the Tropic of Capricorn from the east coast of Australia to longitude 150°W, thence by the meridian of longitude 150°W, to latitude 20°S and thence by the parallel of latitude 20°S to the point where it intersects the southern boundary of the Tropical Zone;

    on the west by the boundaries of the area within the Great Barrier Reef included in the Tropical Zone and by the east coast of Australia.

    • Seasonal periods:

      TROPICAL: 1 April to 30 November

      SUMMER: 1 December to 31 March


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