Glossary Archive

A small triangular sail hoisted at the masthead to help stabilise a boat in heavy winds.  A trysail is a small triangular sail that is hoisted at the masthead of a boat to help stabilise the vessel in heavy winds. It is typically used as a storm sail when the wind is too strong for...

A navigation system designed to organise the flow of vessel traffic in congested or high-risk areas, ensuring safe passage by separating opposing traffic streams. A Traffic Separation Scheme (TSS) is a regulatory measure established by the International Maritime Organization (IMO) to enhance maritime safety in areas where vessel traffic is dense or where there is...

Estimated time remaining to a waypoint giving an indication of arrival time

When a rope passes around an object, such as a post, when tying a knot.

Sea area of the Met Office Shipping Forecast. Covers the southwestern North Sea, off the River Tyne estuary in northeast England. From the River Tyne estuary (Brythonic origin), Tyne typically has moderate northwesterlies of Force 3–5 and slight seas, with stronger winds in autumn and winter. A North Sea surge in January 1953 caused high...

A region of the Earth where the same standard time is used. A time zone is a geographical area that observes a uniform standard time for legal, commercial, and social purposes. The Earth is divided into 24 primary time zones, each generally corresponding to 15 degrees of longitude, reflecting the Earth's rotation and the division...

The International Maritime Signal Flag Uniform. Meaning You are running into danger.

The UK government agency responsible for producing nautical charts, publications, and navigational information to support safe maritime navigation.  The UK Hydrographic Office is an executive agency of the UK Ministry of Defence, providing hydrographic and geospatial data for both military and commercial maritime use. It produces and maintains Admiralty charts and publications, which are widely...

The UK government agency responsible for producing nautical charts, publications, and navigational information to support safe maritime navigation.  The UK Hydrographic Office is an executive agency of the UK Ministry of Defence, providing hydrographic and geospatial data for both military and commercial maritime use. It produces and maintains Admiralty charts and publications, which are widely...

The global numerical weather prediction model developed by the United Kingdom Met Office, providing forecasts for various weather parameters worldwide.  The UKMO Global model is a sophisticated numerical weather prediction system developed by the United Kingdom Met Office. It utilises advanced mathematical equations to simulate the Earth's atmosphere and predict future weather conditions globally. This...