Daggerboard, Dan Buoy, Danforth Anchor, Davits, Daybeacon, Daymark,
Dayboat, Daysailer, Day Shape, Dead, Dead Ahead, Dead Astern, Dead-Downwind,
Deadeye, Dead-In-The-Water, Deadlight, Dead Reckoning, Dead-Run, Dead Stop,
Dead Water, Dead Wind, Deck, Deckhead, Deck Hand, Deck Stepped,
Declination, Deflection, Deflecting Force, Depower, Deploy, Depth,
Depth Sounder, Design-Water-Line, Deviation, Diaper, Dig-In, Dinghy,
Dipping Lug, Dip-Pole-Jibe, Directional Antenna, Direction Finder,
Direction Of Current, Directive, Dirty Wind, Disembark, Dismast,
Displacement Hull, Displacement Speed, Distance-Made-Good, Distress Signals,
Distressed Vessel, Ditty Bag, Diurnal, Dive Flag, Dividers, Dock,
Dock Lines, Dock Master, Dodger, Doghouse, Dog Watch, Doldrums, Dorade Vent,
Dory, Double Ender, Douse, Downhaul, Downwind, Draft, Draft Position, Drag,
Draw, Draw String, Dredge, Drift, Drogue, Drop Anchor, Drop Keel, Dry Dock,
D-Shackle, Dumb Compass, Dye Marker.
DAGGERBOARD
Similar to a Centerboard, except that it is raised vertically
instead of pivoting.
DAN BUOY
A light non-stationary Buoy having a single Spar with a float and weight
at the bottom, used to temporarily Mark areas on the water such as a
diver's location, Hazards and obstructions, the end of a starting
line in a Regatta, and other purposes.
(Also, see CAN BUOY and NUN BUOY)
DANFORTH ANCHOR
(Meon Anchor)
A lightweight Anchor with a rod-like Stock that passes through the Crown,
to which the pivoting Flukes are attached. A Danforth Anchor is known for
its outstanding Holding Power.
(Also, see KEDGE ANCHOR and PLOW ANCHOR)
DAVIT
A crane-like device that projects out and beyond the sides of a vessel,
used for raising, lowering, or supporting objects such as anchors,
cargo, life boats, etc.
DAYBEACON
An unlighted Navigational Aid used as a Daymark.
DAYBOAT
(See DAYSAILOR)
DAYMARK
A Navigational Aid distinctively marked for visibility by day.
[e.g., In the United States and Canada, red square Daymarks are always
to the right or Starboard of the boat when returning from Sea, and
green triangular Daymarks are always to the left or Port side
when returning from Sea.]
(Also, see CAN BUOY and NUN BUOY)
DAYSAILER
(Dayboat)
Any of a variety of small sailboats used primarily for short
cruises during the day.
(Also, see POCKET CRUISER)
DAY SHAPE
a navigation visual aid (i.e., black silhouettes) displayed on
Vessels during daylight hours to indicate a Vessel's Course
and/or occupational operation.
(Also, see SHAPE)
DEAD
A mariner's term to indicate "directly" or "exactly" that which is stated.
[e.g., "Be ready to Bear Away from the object Dead Ahead.")
DEAD-AHEAD
1. Directly in front of the Bow and exactly in line with the Centerline.
2. A relative heading of 000°.
DEAD-ASTERN
Directly behind the Stern and exactly in line with the Centerline.
DEAD-DOWNWIND
(See DEAD-RUN)
DEADEYE
Either of a pair of disks of hardwood having holes through which a
Lanyard is Rove, used mostly on tall ships to tighten Shrouds and
Stays.
DEAD-IN-THE-WATER
To be Adrift and without power or the means to Steer the Vessel.
(Also, see VESSEL-NOT-UNDER-COMMAND)
DEADLIGHT
1. A strong storm shutter that is screwed against the interior of a
Porthole during Heavy Weather.
2. A thick pane of glass set in the Hull or Deck to admit light.
DEAD RECKONING
(DR)
Dead Reckoning (DR) is a daily estimation of the Course a Vessel has
traveled from a known reference point, using Compass and Log to plot
the Course and Distance-Made-Good on a Chart to determine the Vessel's
location at Sea. Dead Reckoning or Estimated Position is only as
accurate as the notations in the Log-Book recording the time of every
change of Course and Log reading of Distance-Made-Good Through-The-Water.
(Also, see CELESTIAL NAVIGATION and COASTAL NAVIGATION)
DEAD-RUN
(Dead-Downwind)
Sailing with the Wind Dead-Astern.
(Also, see BEFORE-THE-WIND, RUN, RUNNING, and SAILING-ON-A-RUN)
DEAD STOP
A Depowered Vessel without Carry.
DEAD WATER
Water Eddying beside a moving Hull, especially Astern.
DEAD WIND
When there's no Wind to power the Sail.
(Also, see DOLDRUMS)
DECK
(Weather Deck)
The exposed horizontal floorlike outer surface of the Vessel, Topsides,
where the boat is steered and Crew activity takes place.
(Also, see FOREDECK)
DECKHEAD
(Ceiling)
The undersurface of the Deck as viewed from the Cabin below.
DECK HAND
(See HAND)
DECK STEPPED
A Mast that is fastened to the Deck of a boat rather than Stepped
through the Deck and attached to the Keel.
DECLINATION
The angular distance of a Heavenly Body from the Celestial Equator,
measured on the Great Circle passing through both the Celestial
Pole and the Heavenly Body.
DEFLECTION
The amount of Deviation from a standard point or 0.
DEFLECTING FORCE
(See CORIOLIS EFFECT)
DEPLOY
To systematically come into position or put things in order
so as to make ready for something to happen or prepare for use.
[e.g., "Deploy the Ground Tackle and be ready to Drop Anchor."]
(Also, see BEND ON)
DEPOWER
To shut off the engine and/or let the Wind out of the Sails.
DEPTH
1. The vertical distance from the Waterline to the Bottom.
(Also, see Depth Sounder, Lead Line, and Soundings)
2. The Camber or fullness of a Sail.
(Also, see CHORD and DRAFT POSITION)
DEPTH SOUNDER
An instrument using sound waves to measure distance from the Vessel to
the Bottom.
DESIGN-WATER-LINE
(DWL)
The length of a boat's Waterline when loaded to its designed capacity.
(Also, see LOAD-WATER-LINE (LWL).
DEVIATION
Deviation is the angle between Compass Bearing and Magnetic Meridian.
(Also, see COMPASS DEVIATION)
DIAPER
A floating device that is attached to the Masthead to allow the Mast
to stay afloat at water level after a Knockdown.
[A diaper is used mostly on Planing Vessels such as Scows.]
DIESEL ENGINE
Inboard auxiliary power used on most Keel Boats.
DIG-IN
(Digging-In)
Term used by Scow sailors characterizing the maneuver of deliberately
Heeling the boat by sitting on the low (Leeward) side, with no one
Hiking-Out on the high (Windward) side.
DINGHY
(Dink)
1. A small open boat, with oars or small outboard engines, often used as
a Tender for larger craft.
2. A small Planing Hull Sailboat without a Cabin.
DIPPING LUG
(See LUGSAIL)
DIP-POLE-JIBE
A maneuver performed by Foredeck Crew during a Spinnaker Jibe, where
the original Working Guy is disengaged from the Jaws of the Outboard
end of the Spinnaker Pole while the inboard end of the pole remains
secured to the Mast, the outboard end is dropped down (Dipped) so that it
can pass beneath the Forestay from one side of the boat to the other,
after which the Lazy Guy is subsequently inserted into the Jaws so as
to make ready to raise the outer end of the pole to complete the Jibe.
DIRECTIONAL ANTENNA
A loop or ferrite rod antenna Mounted on the Mast of a Vessel,
used as part of a Direction-Finder to locate the Bearing of
a Radio Beacon.
DIRECTION FINDER
(See RADIO-DIRECTION-FINDER)
DIRECTION OF CURRENT
(See SET)
DIRECTIVE
(Authoritative Instruction)
[e.g., Information originating from an authority such as Securite.]
(Also, see COMMAND and ORDER)
DIRTY WIND
(See WIND SHADOW)
DISEMBARK
To go Ashore from a Vessel.
(Also, see BOARD)
DISMAST
A term indicating the loss of a Mast on a Sailboat.
DISPLACEMENT
The weight of water displaced by a Vessel.
DISPLACEMENT HULL
A boat with a Keel.
(Also, see PLANNING HULL)
DISPLACEMENT SPEED
(Hull Speed)
The speed a monohull sailboat can travel without planing, based on
the shape of its Hull. The speed is calculated at 1.34 times the
length of its waterline.
DISTANCE-MADE-GOOD (DMG)
(Made Good)
A navigation term indicating the distance traveled Over-The-Ground
(i.e., over the Bottom) as opposed to distance traveled Through-The-Water.
Distance-Made-Good (DMG) is derived after correcting for Current,
Leeway, and other errors that may not have been included in the
original calculation of Nautical distance.
DISTRESS SIGNALS
Flags, flares, smoke, audible alarms, electronic beacons and other
devices used to indicate a Vessel-In-Distress.
DISTRESSED VESSEL
(See VESSEL-IN-DISTRESS)
DITTY BAG
An old-fashioned small canvas bag sailors of yore used to carry their
personal effects.
(Also, see SAILORS KIT)
DIURNAL
The Tide is Diurnal when only one High-Water (HW) and one
Low-Water (LW) occur during a Tidal Day. The Tidal Current
is Diurnal when only a single Flood and Ebb occur during
a Tidal Day.
(Also, see SEMIDIURNAL)
DIVE FLAG
An Alpha flag (i.e., a white and blue swallow-tailed code flag)
displayed on a boat or other floating device when divers are in
the water.
DIVIDERS
An instrument used to measure distance on a Chart.
(Also, see COMPASSES)
DOCK
An enclosed area of Piers or Wharfs where Vessels are Moored.
(Also, see SLIP)
DOCKLINES
Lines used for Mooring at a Pier.
DOCKMASTER
A supervisor of Berthing operations at a Yacht Club or Marina.
(Also, see HARBORMASTER)
DODGER
(Windscreen)
A canvas or polymer cover, with transparent window slots, used to
protect the cockpit from wind and spray.
(Also, see BIMINI and PILOT HOUSE)
DOGHOUSE
The top and sides of a Sailboat Cabin with a high profile above Deck.
(Also, see TRUNK CABIN)
DOG WATCH
The late afternoon part of the Watch Cycle, which is divided into two hour
watches, the First Dog Watch being 1600-1800 hours, and the Last Dog Watch
being 1800-2000 hours.
DOLDRUMS
(Dead Wind)
The Ocean regions north of the Equator, between the northern and
southern Trade Winds in the Atlantic and Pacific oceans, where
there is little or no Wind.
DORADE VENT
A type of vent designed to let air into a Cabin and keep water out
by the use of baffles.
(Also, see COWLS)
DORY
A small row boat with a narrow flat bottom, high Bow, and flaring
sides. Used primarily for transporting people, gear, and supplies
to and from Shore and/or other craft.
DOUBLE ENDER
A Vessel's Stern shaped the same as its Bow, usually pointed.
DOUBLE UP
To Rig extra Mooring Lines.
DOUSE
To lower or drop sails quickly.
DOWNHAUL
1. A Line used to Trim the Luff of a Sail.
(Also, see CUNNINGHAM)
2. Line and bridle attached to the Spinnaker Pole for the purpose of
keeping the pole from rising up during a Spinnaker Set.
(Also, see FOREGUY)
DOWNWIND
Sailing Leeward on a Run, not necessarily on a Dead-Run.
DRAFT
1. The vertical distance from the bottom of the Keel to the Waterline.
(Also, see DRAW)
2. The apex in the curvature of a Sail that moves when Trimmed.
(Also, see CAMBER and DRAFT POSITION)
DRAFT POSITION
The position of the sail's deepest point. That is, the percentage of
the distance the sail's deepest point is from the Luff to the length
of the Chord.
(Also, see CHORD)
DRAG
1. Drag occurs when the Anchor fails to Hold and the boat moves
the Anchor over the Sea-Bed.
2. Friction or resistance.
DRAW
1. The minimum depth of water matching the Vessel's Draft, in which the
Keel will not touch the Bottom.
2. The degree to which the Sail is catching the wind and propelling
the Vessel.
[e.g., When sailing with only the Mainsail in light wind, Angle-Of-Attack
must be increased significantly in order for the Sail to Draw on the
Apparent Wind. When the Vessel is Under Way, Draw is reduced due to
the lack of Headwind resulting from the boat’s forward motion.]
DRAWSTRING
(See LEECH LINE)
DREDGE
1. To deepen the Bottom of a Waterway.
2. A Vessel designed for Dredging.
DRIFT
1. The velocity of a Current.
2. The distance a Vessel is carried by a Current.
3. A Vessel moving in the water without power.
DROGUE
An open-ended cone shaped underwater device used to increase the Drag
of a Vessel during Heavy Weather.
(Also, see SEA ANCHOR)
DROP ANCHOR
(Come-To-Anchor)
To deploy the Anchor and letting it descend to the Bottom.
DROP KEEL
(See RETRACTABLE KEEL)
DRY DOCK
1. A Dock with a Lock where water is drained off so that the outer
Hull of a Vessel can be worked on.
2. A term used to indicate when a boat has been pulled out of the
water and stored on land.
D-SHACKLE
A straight-sided Shackle.
(Also, see HARP SHACKLE)
DUMB COMPASS
(See PELORUS)
DYE MARKER
Orange dye that is released from a container and spread on the surface
of the water used to signal aircraft that a Vessel or person needs to
be rescued.
