Yacht Auriga - about the planned South Atlantic Expedition by our very own Giulia, Igor and Matt
Sailing Anarchy - fast boats & the real stories, and heated discussions on the message board
Seattle Yachts - A kids guide to sailing that introduces almost everything from first principles
Marine Accident Investigation Branch - objective analysis of accidents at sea. Learn from the mistakes of others.
Animated Knots - "Better to know a knot and not need it, than need a knot and not know it."
Splicing Guide - from New England Ropes, covering modern as well as traditional braids.
Easytide - official UKHO website, free 7-day tidal height predictions
Tidetimes - free 7-day tidal height predictions based on UKHO models
YR.NO - shows tidal streams ("Havstrømmer", or use Google Translate) for the UK and Northern Europe
Navionics Webapp - free worldwide vector charts (online only) from a leading supplier. Your chartplotter at home.
VisitMyHarbour - many free Admiralty charts for the UK, plus aerial photographs - a useful pilotage aid
EastCoastPilot - download up-to-date chartlets for many East Coast rivers, and avoid those shifting sands
Deben Estuary Pilot - by the Deben Harbour Master
Metoffice marine weather - official shipping & inshore waters forecasts, surface pressure charts from the source
BBC Coast and Sea - an alternative take on the same
Windguru - detailed wind forecast for coastal locations worldwide, based on a high-res GFS model and local corrections
XCWeather - UK wind and weather at a glance.
Passageweather - wind and waves plotted over large areas, great for passage planning. Different weather models, tropical weather warnings, worldwide pilot charts
Earth - beautiful visualization of winds and ocean currents worldwide. A geek's delight - choose map projection, ponder the hairy ball theorem, see the jetstream, locate the elusive Golfstream.
Weathercharts - huge collection of links to different surface pressure analysis charts, satellite images etc.
Weatherspark - more landbased, but great for finding the average temperature, wind or rainfall in Stornoway in July. Historic averages and forecasts plotted in an intuitive way.
Windfinder - short-time, high-resolution forecasts.
YR.NO - great weather map from the Norwegians. Wind, temperature, waves, UV, ...
Bramblemet - live from the Solent, great for racing