tides, currents, and leeway 101
- Enter Table 2 (substations). Enter Table 2 with your substation number.
Look at the middle columns showing time and height diff erences. Write
this information down. Look directly above your substation line. You’ll see
the name of the Table 1 reference station in bold print, along with a page
number. Turn to this page. - Enter Table 1 (reference stations). Th e page number lands you onto the
month of January. Flip through the pages to fi nd the month and date you
need. Copy the time and heights. Add or subtract the substation time
diff erences to the reference station high- and low-water times. Add or
subtract the substation height diff erences to the reference station high- and
low-water heights. (Occasionally you will see an asterisk in the substation
height diff erence column. Th is means you must multiply the number shown
by the applicable reference station high- or low-water heights. For example,
if you fi nd “*0.6” under the substation high-water column, multiply each
reference station high-water height by 0.6.)
BRITISH ADMIRALTY AND FOREIGN TIDE TABLES
British Admiralty tide tables are intuitive and easy to follow. Note the few
minor differences from the U.S. government tide tables:
Station names. Reference Stations are called standard ports. Substations are
called secondary ports.
Times. British ports use Greenwich Mean Time (GMT). (In the near future,
this will be listed as Coordinated Universal Time [UTC]). Foreign ports use
the time zone of that country.
Heights. Heights are given in meters. Add or subtract height diff erences based
on their sign (+ or –). Diff erences are listed under four columns:
MHWS = Mean High Water Springs
MHWN = Mean High Water Neaps
MLWS = Mean Low Water Springs
MLWN = Mean Low Water NeapsSEA-CRET TIP
X U.S. and British Admiralty tide tables list reference station (or
standard port) times, respectively, in Eastern Standard Time (EST)
or Greenwich Mean Time (GMT). Remember to add 1 hour during
periods of Daylight Savings Time (DST).