Maritime Navigation Rules & Vessel Lighting Study Guide for Seafarers
NUC Not Under Command - Unable to maneuver
as required because of an exceptional
circumstance.
RAM Restricted in Ability to Maneuver - Restricted
in ability to maneuver because of the nature
of her work.
CBD Constrained by Draft - A power-driven vessel
severely restricted in her ability to deviate
from the course she is following because of
her draft in relation to the available depth
and width of navigable water.
Fishing Vessel A vessel fishing with nets, lines, trawls, or
other fishing apparatus that restrict
maneuverability.
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, Maritime Navigation Rules & Vessel Lighting Study Guide for Seafarers
Sailing Vessel A vessel under sail, provided propulsion
machinery, if fitted, is not being used.
PDV Power-Driven Vessel - Any vessel propelled
by machinery.
Underway A vessel that is NOT at anchor, made fast to
shore, or aground.
Making Way Underway + moving through the water.
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NUC Not Under Command - Unable to maneuver
as required because of an exceptional
circumstance.
RAM Restricted in Ability to Maneuver - Restricted
in ability to maneuver because of the nature
of her work.
CBD Constrained by Draft - A power-driven vessel
severely restricted in her ability to deviate
from the course she is following because of
her draft in relation to the available depth
and width of navigable water.
Fishing Vessel A vessel fishing with nets, lines, trawls, or
other fishing apparatus that restrict
maneuverability.
Page 1 of 8
, Maritime Navigation Rules & Vessel Lighting Study Guide for Seafarers
Sailing Vessel A vessel under sail, provided propulsion
machinery, if fitted, is not being used.
PDV Power-Driven Vessel - Any vessel propelled
by machinery.
Underway A vessel that is NOT at anchor, made fast to
shore, or aground.
Making Way Underway + moving through the water.
Page 2 of 8
