Glossary of Nautical Terms - H

H

Half-breadth plan

In shipbuilding, an elevation of the lines of a ship, viewed from above and divided lengthwise.

Halyard or halliard

Originally, ropes used for hoisting a spar with a sail attached; today, a line used to raise the head of any sail.

Hammock

Canvas sheets, slung from the deckhead in messdecks, in which seamen slept. "Lash up and stow" a piped command to tie up hammocks and stow them (typically) in racks inboard of the ship's side to protect crew from splinters from shot and provide a ready means of preventing flooding caused by damage.

Hand

To furl a sail.

Handy billy

A loose block and tackle with a hook or tail on each end, which can be used wherever it is needed. Usually made up of one single and one double block.

Hand bomber

A ship using coal-fired boilers shoveled in by hand.

Hand over fist

To climb steadily upwards, from the motion of a sailor climbing shrouds on a sailing ship (originally "hand over hand").

Handsomely

With a slow even motion, as when hauling on a line "handsomely".

Hangar deck

An enclosed deck, usually beneath the flight deck, on an aircraft carrier intended for use as a hangar in servicing and storing aircraft.

Hank

A fastener attached to the luff of the headsail that attaches the headsail to the forestay. Typical designs include a bronze or plastic hook with a spring-operated gate, or a strip of cloth webbing with a snap fastener.

Harbor

A harbor or harbour, or haven, is a place where ships may shelter from the weather or are stored. Harbours can be man-made or natural.

Harbor of refuge

A place where ships in transit can find shelter from a storm. These are often man-made jetty enclosed areas along a featureless coastline where no nearby natural deep water harbors exist.

Hard

A section of otherwise muddy shoreline suitable for mooring or hauling out.

Hard-a-lee

See lee-oh.

Harden up

Turn towards the wind; sail closer to the wind.

Harness cask

A large usually round tub lashed to a vessel's deck and containing dried and salted provisions for daily use.

Harness tub

See "Harness cask".

Hardtack

A hard and long-lasting dry biscuit, used as food on long journeys. Also called ship's biscuit.

Hatchway, hatch

A covered opening in a ship's deck through which cargo can be loaded or access made to a lower deck; the cover to the opening is called a hatch.

Hauling wind

Pointing the ship towards the direction of the wind; generally not the fastest point of travel on a sailing vessel.

Hawsepipe, hawsehole or hawse (/ˈhɔːz/)

The shaft or hole in the side of a vessel's bow through which the anchor chain passes.

Hawsepiper

An informal term for a merchant ship’s officer who began their career as an unlicensed merchant seaman, and so did not attend a traditional maritime academy to earn their officer's licence (also see before the mast).

Hawser

Large rope used for mooring or towing a vessel.

Head

1. The toilet or latrine of a vessel, which in sailing ships projected from the bows.

2. The top edge of a sail.

Head boat

A fishing boat that takes recreational fishermen out for a fee paid individually by each person (i.e., per head). A head boat differs from a charter boat, which is a fishing boat that a party of fishermen hires for an agreed-upon period.

Header

A change in the wind direction which forces the helmsman of a close hauled sailboat to steer away from its current course to a less favorable one. This is the opposite of a lift.

Head of navigation

The farthest point above the mouth of a river that can be navigated by ships.

Head rail

A curved rail that extends from the figurehead to the bow of a ship.

Head sea

A sea where waves are directly opposing the motion of the ship.

Headsail

Any sail flown in front of the most forward mast.

Heave

A vessel's transient, vertical, up-and-down motion.

Heaving to

Stopping a sailing vessel by lashing the helm in opposition to the sails. The vessel will gradually drift to leeward, the speed of the drift depending on the vessel's design.

Heave down

Turn a ship on its side (for cleaning). Also known as Careening

Heeling

Heeling is the lean caused by the wind's force on the sails of a sailing vessel.

Helm

A ship's steering mechanism; see tiller and ship's wheel. The wheel and/or wheelhouse area. Also see wheelhouse.

Helmsman

A person who steers a ship.

Herring buss

A type of seagoing fishing vessel used by Dutch and Flemish herring fishermen from the 15th through the early 19th century.

Highfield lever

A particular type of tensioning lever, usually for running backstays. Their use allows the leeward backstay to be completely slackened so that the boom can be let fully out.

Hitch

A knot used to tie a rope or line to a fixed object. Also see bend.

Hog

1. A fore-and-aft structural member of the hull fitted over the keel to provide a fixing for the garboard planks.

2. A rough flat scrubbing brush for cleaning a ship’s bottom under water.

Hogging

When the peak of a wave is amidships, causing the hull to bend so the ends of the keel are lower than the middle. The opposite of sagging. Also refers to a permanent distortion of the hull in the same manner caused, over time, by the bow and stern of a ship being less buoyant than the midships section. During the Age of Sail, shipwrights employed a number of different designs of braces to stiffen ships' hulls against this warping.

Hold

In earlier use, below the orlop deck, the lower part of the interior of a ship's hull, especially when considered as storage space, as for cargo. In later merchant vessels it extended up through the decks to the underside of the weather deck.

Holiday

A gap in the coverage of newly applied paint, slush, tar or other preservative.

Holystone

A chunk of sandstone used to scrub the decks. The name comes from both the kneeling position sailors adopt to scrub the deck (reminiscent of genuflection for prayer), and the stone itself (which resembled a Bible in shape and size).

Horn

A sound signal which uses electricity or compressed air to vibrate a disc diaphragm.

Horn timber

A fore-and-aft structural member of the hull sloping up and backwards from the keel to support the counter.

Horse

1. Attachment of sheets to deck of vessel (main-sheet horse).

2. (v.) To move or adjust sail by brute hand force rather than using running rigging.

Hotel load

The base amount of electricity needed to work the ship.

Hounds

Attachments of stays to masts.

Hulk

1. A ship, often an old ship or one that has become obsolete or uneconomical to operate, that has had its rigging or internal equipment removed and is incapable of going to sea, but that is afloat and continues to serve a useful function, such as providing living, office, training, storage, or prison space.

2. To convert a ship into such a hulk.

3. Less commonly, a ship that has been launched but not completed.

4. Also less commonly, an abandoned wreck or shell of a ship.

Hull

The shell and framework of the basic flotation-oriented part of a ship.

Hull-down

Of a vessel when only its upper parts are visible over the horizon.

Hull speed

The maximum efficient speed of a displacement-hulled vessel.

Hydrofoil

A boat with wing-like foils mounted on struts below the hull, lifting the hull entirely out of the water at speed and allowing water resistance to be greatly reduced.