Port tack To sail with the wind on the port side.
RACON Beacon giving characteristic signal when triggered by a vessel’s radar set.
Range A line formed when two objects are in line, one behind the other.
Range
of Tide The difference in height between consecutive high and low waters, the mean range is the differ-
ence in height between mean high water and mean low water. Where the type of tide is diurnal,
the mean range is the same as the diurnal range.
Reach The courses of a sailing vessel between close-hauled and running.
Reef To reduce sail area.
Reference
Station A tide or current station for which independent daily predictions are given in the Tide Tables and
Tidal Current Tables, and from which corresponding predictions are obtained for subordinate
stations by means of differences and ratios.
Reversing
Current A tidal current that flows alternately in approximately opposite directions with a slack water at
each reversal of direction.
Rotary
Current A tidal current that flows continually with the direction of flow changing through all points of the
compass during the tidal period. Rotary currents are usually found offshore where the direction
of flow is not restricted by any barriers.
SEMIDIURNAL The predominating type of tide throughout the world is semidiurnal, with two high waters and
two low waters each tidal day.
Set
(of current) The direction toward which the current flows.
Slack Water The state of a tidal current when its speed is near zero.
Sound To measure the depth of water by lead line or electronic means.
Spring A mooring line that prevents a vessel moving fore and aft when tied up alongside a dock; e.g.,
an after spring is attached to the stern of the vessel and led to a bollard on the dock forward of
the vessel to prevent it moving astern.
Spring Tides
/Currents Tides of increased range or tidal currents of increased speed occurring semimonthly as the result
y
of the Moon being new or full.
Stand of Tide An amount of time at high or low water when there is no noticeable change in the height of the
tide.
Glossar
Stand on To maintain course and speed.
Standard
Time A kind of time based upon the transit of the sun over a certain specified meridian, and adopted
for use over a considerable area. With a few exceptions, standard time is based upon some me-
ridian that differs by a multiple of 15° from the meridian of Greenwich.
Starboard The right hand side of a ship facing forward.
Starboard lanning
tack With the wind on the starboard side.
P
Subordinate
Current
Station A station listed in the Tidal Current Tables, for which predictions are to be obtained by means of
differences and ratios applied to the full predictions at a reference station.
Subordinate
Tide Station A station listed in the Tide Tables, for which predictions are to be obtained by means of differ-
ences and ratios applied to the full predictions at a reference station.
TIDAL
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