INTRODUCTORY.

DEPARTMENT OF COMMERCE,

U. S. COAST AND GEODETIC SURVEY,

Washington, D. C., November 1, 1921.

This volume covers the islands of Porto Rico and the Virgin Islands. It is based mainly upon the work of the United States Coast and Geodetic Survey, including the results of a special examination in 1920. The descriptions of the British Virgin Islands are taken mainly from the British Admiralty publication, The West Indies Pilot, Part II, 1920, with additions from Hydrographic Office Publications.

The first edition (Porto Rico, 1906) covered only the islands of Porto Rico, Mona, and Vieques, but this edition is enlarged to include the recently American possessions in the Virgin Islands and the British Virgin Islands. The present edition has been prepared by Paul C. Whitney, Chief, Coast Pilot Section, U. S. Coast and Geodetic Survey.

Great courtesy has been shown by the United States Lighthouse Service, the United States Engineers, and local authorities in furnishing information for use in this publication.

The aids to navigation are corrected to October 21, 1921.

Navigators are requested to notify the Director of the U. S. Coast and Geodetic Survey of any errors or omissions they find in this publication, or of additional matter which they think should be inserted for the information of mariners.

E. LESTER JONES,

Director.

NOTE.

The courses and bearings given in degrees are true, reading clockwise from 0° at north to 360°, and are followed by the equivalent magnetic value in points in parentheses. General directions, such as northeastward, west-southwestward, etc., are magnetic.

Distances are in nautical miles, and may be converted approximately to statute miles by adding 15 per cent to the distances given. Currents are expressed in knots, which are nautical miles per hour. Except where otherwise stated, all depths are at mean low water. Supplements and other corrections for this volume are issued from time to time and will be furnished, free of charge, on application to the Coast and Geodetic Survey, Washington, D. C., provided the volume itself has not been superseded by a subsequent edition.

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