In
sailing, a course sail is the principal sail on a mast. This term is used predominantly on
square rigged vessels, referring to the largest and lowest sail on each mast (mizzen-course, main-course and fore-course).
Gaff-rigged vessels might possibly use the term (for the lowest sail rigged aft of each mast), but are more likely to refer simply to a mainsail, foresail, etc. A
Bermuda- or lateen-rigged yacht, whether
sloop,
cutter,
ketch or
yawl, would not usually be described as having a course.
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