---
kind: "section"
citation: "46 C.F.R. § 42.30-15"
title: "46"
number: "42.30-15"
heading: "Tropical Zone."
url: "https://uscodex.org/cfr/46/42.30-15"
---

# §42.30-15. Tropical Zone.

- (a) **Northern boundary of the Tropical Zone.** The northern boundary of the Tropical Zone is the parallel of latitude 13° N. from the east coast of the American continent to longitude 60° W.; thence the rhumb line to a point in latitude 10° N., longitude 58° W.; thence the parallel of latitude 10° N. to longitude 20° W.; thence the meridian of longitude 20° W. to latitude 30° N.; thence the parallel of latitude 30° N. to the west coast of Africa; from the east coast of Africa the parallel of latitude 8° N. to longitude 70° E.; thence the meridian of longitude 70° E. to latitude 13° N.; thence the parallel of latitude 13° N. to the west coast of India; thence around the south coast of India to latitude 10°30′ N. on the east coast of India; thence the rhumb line to a point in latitude 9° N., longitude 82° E.; thence the meridian of longitude 82° E. to latitude 8° N.; thence the parallel of latitude 8° N. to the west coast of Malaysia; thence the coast of Southeast Asia to the east coast of Vietnam at latitude 10° N.; thence the parallel of latitude 10° N. to longitude 145° E.; thence the meridian of longitude 145° E. to latitude 13° N.; and thence the parallel of latitude 13° N. to the west coast of the American continent.
  - (1) Saigon is to be considered as being on the boundary line of the Tropical Zone and the Seasonal Tropical Area.
- (b) **Southern boundary of the Tropical Zone.** The southern boundary of the Tropical Zone is the rhumb line from the Port of Santos, Brazil, to the point where the meridian of longitude 40° W. intersects the Tropic of Capricorn; thence the Tropic of Capricorn to the west coast of Africa; from the east coast of Africa the parallel of latitude 20° S. to the west coast of Madagascar; thence the west and north coasts of Madagascar to longitude 50° E.; thence the meridian of longitude 50° E. to latitude 10° S.; thence the parallel of latitude 10° S. to longitude 98° E.; thence the rhumb line to Port Darwin, Australia; thence the coasts of Australia and Wessel Island eastwards to Cape Wessel; thence the parallel of latitude 11° S. to the west side of Cape York; from the east side of Cape York the parallel of latitude 11° S. to longitude 150° W.; thence the rhumb line to the point latitude 26° S., longitude 75° W.; and thence the rhumb line to the west coast of the American continent at latitude 30° S.
  - (1) Coquimbo and Santos are to be considered as being on the boundary line of the Tropical and Summer Zones.
- (c) **Areas to be included in the Tropical Zone.** The following areas are to be treated as included in the Tropical Zone:
  - (1) **The Suez Canal, the Red Sea, and the Gulf of Aden, from Port Said to the meridian of longitude 45° E.**
    - (i) Aden and Berbera are to be considered as being on the boundary line of the Tropical Zone and the Seasonal Tropical Area.
  - (2) **The Persian Gulf of the meridian of longitude 59° E.**
  - (3) **The area bounded by the parallel of latitude 22° S.** from the east coast of Australia to the Great Barrier Reef, thence the Great Barrier Reef to latitude 11° S. The northern boundary of the area is the southern boundary of the Tropical Zone.

## Notes

### Amendments

[CGFR 68-60, 33 FR 10068, July 12, 1968]

### Authority

Authority: 46 U.S.C. 5101-5116; Department of Homeland Security Delegation No. 00170.1, Revision No. 01.4; section 42.01-5 also issued under the authority of 44 U.S.C. 3507.

### Amendments

[CGFR 68-60, 33 FR 10068, July 12, 1968]