Glossary of Nautical Terms - I

I

Icebreaker

A special-purpose ship or boat designed to move and navigate through ice-covered waters.

Icing

A serious hazard where cold temperatures (below about -10°C) combined with high wind speed (typically force 8 or above on the Beaufort scale) result in spray blown off the sea freezing immediately on contact with the ship

Idlers

Members of a ship's company not required to serve watches. These were in general specialist tradesmen such as the carpenter and the sailmaker.

Inboard motor

An engine mounted within the hull of a vessel, usually driving a fixed propeller by a shaft protruding through the stern. Generally used on larger vessels. Also see sterndrive and outboard motor.

Inboard-Outboard drive system

See sterndrive.

Inglefield clip

A type of clip for attaching a flag to a flag halyard.

In irons

When the bow of a sailboat is headed into the wind and the boat has stalled and is unable to maneuver.

In ordinary

An 18th- and 19th-century term originally used to refer to a naval vessel out of service for repair or maintenance, later coming to mean naval ships in reserve with no more than a caretaker crew.

In-water survey

A method of surveying the underwater parts of a ship while it is still afloat instead of having to drydock it for examination of these areas as was conventionally done.

In way of

In the vicinity of; in the area of.

Ironclad

A steam-propelled warship protected by iron or steel armor plates of the period from 1859 until the 1890s (when the term "ironclad" fell out of use).

Iron topsail

An auxiliary motor on a schooner.

Iron wind

What sailors call inboard engines.

Island

The superstructure of an aircraft carrier. A carrier that lacks one is said to be flush-decked.