Admiralty Publications (NP Series)

The UK Hydrographic Office (UKHO) publishes a range of essential Admiralty publications, each identified by an NP number. NP5011 (the UK edition of INT1) is the definitive reference for all chart symbols and abbreviations — every navigator should have a copy to hand when reading nautical charts.

NP100, The Mariner's Handbook, provides comprehensive guidance on charts, navigational hazards, weather, tides, and regulations — it is the navigator's 'textbook'. NP136, Ocean Passages for the World, gives recommended routes for ocean passages, taking into account prevailing winds, currents, and ice limits.

Admiralty Sailing Directions (Pilots) are a series of volumes covering the world's coastlines. They describe the coast, harbours, approaches, local conditions, pilotage notes, and anchorages in far greater detail than any chart can show. They are invaluable for passage planning and entering unfamiliar ports.

The Admiralty List of Lights and Fog Signals gives full details of every navigational light worldwide — character, range, structure description, and fog signals. Admiralty Tide Tables provide predicted times and heights of high and low water for standard ports, with data for calculating secondary ports.