Sailwx.info’s real-time map of ship locations (based on data from the Voluntary Observing Ships program) has been getting a lot of play on the web lately — I first saw it on La Cartoteca — but the site has a lot of other information maps as well, including tides, water temperature, wave height and wind speed. Graphically, the maps are quite primitive — numbers superimposed on a two-tone cylindrical projection — but what they lack in presentation they more than make up for in raw information.