I got into Seaclear II last summer while we set out on a 2 week sail from barnegat Light Nj to the chesapeake and back. SearclearII is free and that's hard to beat. I bought a Delorme Earthmate GPS LT-20 with usb connect for $20 online to plug into a Dell notebook running XP. The applications is a bit cryptic to set up but I was pretty pleased once I had it up and running.
My overview to set it up- google & download the SeaClear II application. in the application there are utility applications like "Mapcal_2" in the Seaclear directory.- more about that later. Install the Seaclear application.
Download the NOAA raster charts for the area you want, unzip them in a standalone folder/subdirectory.
Now you need to find, within the the chart files you just "exploded", those that have a .kap ending.
Searclear doesn't need all the files you downloaded from the noaa zip files- just the .kap ending files.
Using Windows Explorer's "Search" function, define the search with a "global" by using *.kap as the name of the file(s) you want found - they will come up in the search results - then "Select ALL" those .kap files and COPY and Paste them to the "charts" subdirectory under the Searclear II directory/folder.
In order to enable Seaclear to know what charts are available to it, and to know what the adjacent chart it needs to load as you sail off the "operating" chart in Seaclear, you need to "register" those charts with Searclear by running the utility "Mapcal_2" - which you use to point to the "charts" directory and run an inventory of all the .kap files for the SeaClear II application. Some files will overlap among the various exploded Noaa .kap files. just allow them to overwrite the duplicate - but you may have a small minority of files- less than 5 per noaa chart download that fail the registry process. I haven't found them to be a critical problem/loss- in my sailing areas .....sofar
There may also be a driver for your usb gps to allow windows to see the virtual usb/com port. This driver usually comes from the gps/hockey puck mfrr. The most hit or miss of the entire process is using the gps' config app and/or Seaclear's config to look at the correct usb/com port - just be patient and try the first 4-5 ports one at a time to see a successful handshake notation.
I found seaclear a lot of fun - i tweaked the width of the bloodline for the "track" history on the chart, i also could change the diameter of the circle around my location for comparative perspective and could also move the cursor around the screen to see me bearing to that position and also the distance to that location. Its easy to zoom in and out of charts for more detail and for dropping waypoints into charts. Its easy to string routes thru varied waypoints and save routes and tracks as you go. Also you could see a Representative "count down graphic" to your next waypoint/turn.
There also exists the possibility to hook up added inputs to the screen- but I'didn't have the connections from external mastop devices. The sailboat we were on had an elaborate $$$ Garman system with wheelpilot and I found my searclear easily gave me the nav info i needed for (almost) free!.
I'd like to try OpenCPN someday soon- but for those that want to try seaclearII I hope this overview was helpful.
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Fast forward to now- i got an ipad2 (wi-fi only) over christmas- and while the admiral plans to use it reading books while on the boat- I plan to load inavx with noaa charts and use a Dual bluetooth xgps150A to supply gps datum to the ipad and use it as a cabin chartplotter. I love these toys! Also I just tried iSailGPS app and a DUAL GPS cradle attachment to my itouch ( wi-fi only) and was pretty impressed how fast it located me. The screen is rather small for convenient use but it was fun to get working.
