Weather Wind & Wave Maps
Use this tool to keep abreast of the current weather conditions worldwide. Check this map just before sailing to check for fast approaching weather patterns. From the right side menu select from 7 data feeds; Live Radar, Wind, Clouds, Temperature, Rain, Waves and the CAPE Index. It works form a network of live feed weather stations and will predict upto 2 days of weather.
Rout Planner / Chart Plotter
OpenSeaMap Ocean Navigation and Route Planner
Coming Soon: This is a great tool for planning your route. It will calculate distance between each waypoint and the total distance of the plan. Combine this with Waterway Guide to find harbors and anchorages that you can plot onto this mapping system. Save your route in CVS, KML or GML format and upload it directly to your ships chart plotter.
Waterway Guide is the most comprehensive database of marinas, anchorages, harbors, bridges, charts and more that any sailor could ask for. I use this like a bible, I can't live without it. If you are not using it you need to try it.