We tried OpenCPN and SeaClear, plus several pay to play applications and settled on Maptech Chart Navigator Pro (which was originally licensed from Rose Point). Since then, Maptech has released their own software and Rosepoint has continued to improve theirs. We upgraded to Coastal Explorer from Rosepoint and it's an amazing piece of software. In addition to pretty significant charting, routing, tracking, instrumentation, etc., it also has full integration with ActiveCaptain and will download all of the ActiveCaptain info for OFFLINE use. Other features that are nice are chart sync (one click and it will check to see if new chart versions are available and download them) and a route timeline (which will let you drag your waypoints backwards and forwards in time and adjust your departure times accordingly - so if you need to make a cut or someplace based upon tide or current you can work backwards). They are also looking to upgrade the route timeline to account for currents. The integrated weather works great (using their own weather server or GRIBs), tides and currents, yada yada yada. Support is excellent too. I'm not related to the company - just love the software.