Barometer Calibration
Calibrate your barometer from anywhere on earth. Gives the 10 closest places with accurate pressure plus a very accurate elevation for those on land. http://www.starpath.com/barometers
Weather Web
A useful source of weather data for UK, Ireland and Europe. Free weekly forecast emails. http://www.weatherweb.net/uksail.htm
Weather forcasts for the Caribbean and Gulf of Mexico
Non-commercial; RSS feeds for hurricane warnings and weather by email. Listing of weather forecasts by SSB HF (time, frequency, area). http://www.nhc.noaa.gov/
Windguru
Free version available. Global wind speed, direction, wave height, direction, cloud cover and rain. Very popular site. http://www.windguru.com
UK Weather Forecasts
Surfline
Free Global Surf and Weather reports. http://www.surfline.com/home/index.cfm