Printable reference
15 essential nautical terms
Three visual sheets covering boat orientation, rules and sailing, movement, depth, and navigation.
Visual glossary · sheet 1 of 3
Know the boat
Fixed sides, ends, and relative directions used in every lookout report and helm order.
Port
Port is the fixed left-hand side of a boat when you face forward toward the bow; its sidelight is red.
PORT and LEFT both have four letters; port wine is red, like the port sidelight.
Starboard
Starboard is the fixed right-hand side of a boat when you face forward toward the bow; its sidelight is green.
Think STEERING SIDE: the old steering oar gives STARBOARD its name.
Bow
The bow is the forward-most part or end of a boat, opposite the stern.
The bow points forward; the stern follows behind.
Stern
The stern is the after or rear end of a boat, opposite the bow.
The sternlight faces the wake behind the boat.
Beam and abeam
Beam is a boat’s greatest width; abeam means approximately 90° to either side of its fore-and-aft line.
BEAM is the crossbar; ABEAM is where that crossbar points.
Ahead and astern
Ahead is the direction beyond the bow; astern is the direction beyond the stern or backward motion.
Bow → ahead. Stern → astern.
Explore the full explanations, examples, and cited sources: boatrules.com/glossary · Fact-checked against the cited sources: July 23, 2026
Visual glossary · sheet 2 of 3
Rules, wind, and sail maneuvers
Encounter roles and wind-relative language that change with the situation.
Stand-on vessel
The stand-on vessel initially keeps course and speed so her actions remain predictable—but she must still avoid collision.
STAND ON predictably—then step in when safety requires it.
Give-way vessel
The give-way vessel is required by the applicable rule to take early and substantial action to keep well clear.
GIVE-WAY goes early and makes the intention obvious.
Windward
Windward means toward the wind or on the side from which the wind is coming.
The WIND reaches the WINDWARD side first.
Leeward
Leeward is the side or direction away from the wind—the downwind side, opposite windward.
A LEE gives shelter; LEEWARD is away from the wind.
Tack
A boat’s tack is named for the side the wind comes from; to tack is to turn the bow through the wind.
TACK: the bow turns through the wind; name it from the side the wind comes from.
Gybe (jibe)
A gybe is a sailing maneuver in which the stern passes through the wind and the sails fill on the opposite side.
Tack: BOW through. Gybe: STERN through.
Explore the full explanations, examples, and cited sources: boatrules.com/glossary · Fact-checked against the cited sources: July 23, 2026
Visual glossary · sheet 3 of 3
Movement, depth, and navigation
Separate legal state from motion, clearance from depth, and the three directions navigators compare.
Underway, making no way
Not at anchor, not made fast, not aground
Making way
Actually moving through the surrounding water
Underway vs making way
Underway is a legal status; making way means actually moving through the surrounding water.
UNDERWAY asks where you are secured; MAKING WAY asks whether water passes the hull.
Draft (draught)
Draft—British spelling draught—is the vertical distance from the waterline to the vessel’s deepest immersed point.
Draft measures DOWN from the waterline; freeboard measures UP.
Heading, course, and bearing
Heading is where the bow points, course describes a travel direction, and bearing points from an observer to an object.
NOSE = heading. PATH = course. LOOK = bearing.
Explore the full explanations, examples, and cited sources: boatrules.com/glossary · Fact-checked against the cited sources: July 23, 2026
Learning aid only — not for navigation. Confirm current rules and local requirements with the relevant authority.