7
General Information
Distances
These are in nautical miles unless otherwise indicated. A nautical mile is 1
minute of latitude, or approximately 2,000 yards, and is about 1.15 statute
miles. See conversion tables in the latter part of this book.
Geographic Positions
Departure and arrival geographic coordinates, where listed, are for a
centrally located pier inside the port.
Routes
These distances are measured along navigable tracklines. Each distance is
along the shortest route that safe navigation permits between the two ports
concerned. The navigator must make their own adjustments for weather or
prevailing currents.
Junction Points
These are positions where two or more routes converge; they are indicated
by magenta CAPITAL LETTERS in the tables. Distances between ports
listed in dierent tables can be obtained by adding the respective distances
to the junction points. Where a port is listed in more than one table,
additional combinations of distances can also be obtained by using the port
as a common reference point. (See examples that follow.)
Foreign Ports
Distances Between Ports, Pub. 151, is published by the National
Geospatial-Intelligence Agency (NGA). NGA Pub 151 is International in
scope and lists distances from foreign port to foreign port, and from foreign
port to major United States ports. The two publications, Distances Between
United States Ports and Distances Between Ports, complement each other.
See the appendix for procurement information.
Examples
The following examples will illustrate the use of the tables. Distances
shown in these examples are in nautical miles.
Ports in the same table
Use of junction and common reference points
Example 4
Find the distance from Bridgeport, CT to Albany, NY.
• Bridgeport to New York (Table 3) is 52 miles
• New York to Albany (Table 5) is 126 miles
• Bridgeport to Albany is 178 miles
Example 5
Find the distance from Woods Hole, MA to Freeport, NY, via the inside
route along the south side of Long Island.
• Woods Hole to Greenport, NY (Table 3) is 82 miles
• Greenport to Freeport (Table 4) is 77
• Woods Hole to Freeport is 159 miles
Example 6
Find the distance from New Haven, CT to Burlington, VT.
• New Haven to New York (Table 3) is 68 miles
• New York to Troy Lock (Table 5) is 134 miles
• Troy Lock to Burlington (Table 6) is 116 miles
• New Haven to Burlington is 318 miles
Example 7
Find the distance from New York, NY to Miami, FL, via the Intracoastal
Waterway.
• New York to Chesapeake and Delaware Canal east entrance
(Table 8) is 190 miles
• Chesapeake and Delaware Canal east entrance to Norfolk Virginia
(Table 10) is 209 miles
• Norfolk to Miami (Table 14) is 947 miles
• New York to Miami is 1,346 miles
Example 8
Find the distance from Boston, MA to San Francisco, CA.
• Boston to Panama Canal (Pacic Entrance) (Table 1) is 2,195 miles
• Panama Canal (Pacic Ent.) to San Francisco (Table 27) is 3,270 miles
• Boston to San Francisco is 5,465 miles
Example 9
Find the distance from Bridgeport, CT to Stockton, CA.
• Bridgeport to New York (Table 3) is 52 miles
• New York to Panama Canal (Pacic Entrance) (Table 1) is 2,018 miles
• Panama Canal (Pacic Ent.) to San Francisco (Table 27) is 3,270 miles
• San Francisco to Stockton (Table 28) is 75 miles
• Bridgeport to Stockton is 5,415 miles
Example 10—nd the distance from Blaine, WA to San Diego, CA.
• Blaine to Cape Flattery (Table 31) is 112 miles
• Cape Flattery to San Diego (Table 28) is 1,104 miles
• Blaine to San Diego is 1,216 miles
Example 1
Find the distance from New York, NY to Charleston, SC.
In Table 1, nd New York, NY, in the list of cities along the left edge
of the table, and Charleston, SC, in the list of cities along the top of
the table. The intersection of the row and column will contain the
distance (630 nautical miles) between these two ports.
Example 2
Find the distance from New Orleans, LA to St. Louis, MO, using Table 20.
• St. Louis mileage is 1,134 statute miles.
• New Orleans mileage is 95 statute miles.
• Subtract 95 from 1,134—New Orleans to St. Louis is 1,039 statute miles.
Example 3
Find the distance from Pittsburgh, PA to Chicago, IL, using Table 20.
• Pittsburgh mileage is 981 statute miles
• The dierence in distance between the Ohio River mouth and the Illinois
River mouth (954 from 1,172) is 218 statute miles
• Chicago mileage is 333
• Add the values together—Pittsburgh to Chicago is 1,532 statute miles