(Chart from inside back cover)

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PILOT CHART OF THE NORTH ATLANTIC OCEAN

The following is a summary of information contained on this chart, and in order that certain items may be more readily identified, they have been numbered and a duplicate number inclosed in a circle placed on the chart as close to the item or feature as practicable:

FRONT

Month of issue.
Date of printing.
Foundation of chart.
[6]Explanation of symbols:
(a) Derelicts and wrecks.
(b) Drifting buoys.
(c) Icebergs and field ice.
(d) Radio stations.
(e) Magnetic variation.
(f) Ocean currents.
(g) Storm tracks.
(h) Prevailing winds and calms.
(i) Scale of wind percentages.
[20]Explanation of inset chart pertaining to normal reduced barometric pressure and normal temperature for the month.
[21]Inset chart showing isobars and isotherms for the month; also annual rate of change in the variation of the compass.
[1]Average conditions of wind and weather during the month.
[9]Local weather.
[4]U. S. storm-warning flags and explanation of use.
[19]Storm signals for Great Britain and France.
[22]Inset chart showing percentages of gales.
Storm tracks.
Wind roses graphically presenting average wind directions and percentages of calms and light airs.
Lines of equal magnetic variation for the epoch 1925.
[13]Lag in U. S. naval radio time signals.
[3]North Atlantic Lane Routes—United States.
[7]North Atlantic Lane Routes—Canada.
Various steamer routes.
Various sailing vessel routes.
Lines of equal fog frequency.
Current arrows.
Trade-wind limits.
Compass rose (true).
Magnetic equator.
Various drifts of derelicts and buoys.
[5]U. S. submarine warning flag.
[11]Communication via U. S. Coast Guard stations.
[12]Note to observers relating to Hydrographic Office publications and blanks for reporting information.
[15]H. O. publications obtainable at the Panama Canal.
[16]List of Branch Hydrographic Offices.
[17]Equator crossings in the North Pacific Ocean for sailing vessels.
Sources of hydrographic and meteorological information.
[14]Note regarding percentage of fog.
[2]Key to storm tracks shown on chart.
[10]Currents north of the Bahamas.
[8]Notes to observers.
[23]U. S. radio-compass stations.
[18]Note on counter equatorial current.

BACK

Fog at sea.