Code of Federal Regulations Title 46. Shipping § 46.42.30–5 Northern Winter Seasonal Zones and area

(1) The North Atlantic Winter Seasonal Zone I lies within the meridian of longitude 50° W. from the coast of Greenland to latitude 45° N.;  thence the parallel of latitude 45° N. to longitude 15° W.;  thence the meridian of longitude 15° W. to latitude 60° N.;  thence the parallel of latitude 60° N. to the Greenwich Meridian, thence this meridian northwards.

(2) The North Atlantic Winter Seasonal Zone II lies within the meridian of longitude 68°30′ W. from the coast of the United States to latitude 40° N.;  thence the rhumb line to the point latitude 36° N., longitude 73° W.;  thence the parallel of latitude 36° N. to longitude 25° W.;  and thence the rhumb line to Cape Torinana. Excluded from this zone are the North Atlantic Winter Seasonal Zone I and the Baltic Sea bounded by the parallel of the latitude of The Skaw in the Skagerrak.

(1) The boundary of the North Atlantic Winter Seasonal Area is the meridian of longitude 68°30′ W. from the coast of the United States to latitude 40° N.;  thence the rhumb line to the southernmost intersection of the meridian of longitude 61° W. with the coast of Canada;  and thence the east coasts of Canada and the United States.

(1) Seasonal periods:

Winter:  October 16 to April 15.

Summer:  April 16 to October 15.