Glossary Archive

A U-shaped flotation device designed to be thrown to a person overboard to provide buoyancy and aid in rescue. The horseshoe lifebuoy, also known as a horseshoe ring or horseshoe buoy, is a critical piece of safety equipment commonly found on recreational and commercial vessels. Its distinctive U-shape allows it to fit snugly around the...

Pronounced: hoh-TELL The term for the letter H in the NATO Phonetic Alphabet.

Attachments of stays to masts.

Any personal flag or club flag flown from starboard spreaders or flagstaff.

The watertight body or shell of a boat or ship, excluding the deck, rigging, and other superstructures. The hull is the fundamental structure of any vessel, designed to provide buoyancy and stability while keeping the water out. It is the part of the boat that makes contact with the water, and its shape and construction...

The maximum efficient speed of a displacement-hulled vessel.

Sea area of the Met Office Shipping Forecast. Lies off the east coast of England, near the Humber Estuary. Named for the Humber Estuary (possibly Celtic for “big water”), Humber sees cyclonic winds of Force 3–5 with occasional sudden gales and tidal surges. The 1953 storm surge overtopped banks, causing widespread damage and leading to...

Beaufort Scale - Force 12 (Hurricane Force 12) Hurricane-force is a term used to describe wind speeds equal to or greater than 64 knots (74 miles or 119 kilometres per hour), the minimum wind speed threshold for a storm to be classified as a hurricane. Winds of this magnitude are capable of causing significant damage...

A lifting surface or structure mounted beneath a vessel's hull that, when moving through water, generates lift to raise the hull above the waterline, reducing drag and increasing speed. A hydrofoil is a specialised marine technology designed to improve the efficiency and performance of watercraft. The hydrofoil itself is a wing-like structure, often made of...

The science of surveying the waters of the earth and adjacent land area, and publishing the results in charts, pilots, etc, for example Admiralty charts