Just did a quick Google search for "download+CM93+chart" and found a couple of sites with FREE downloads. Some time back I was given a disk with the CM93 on it. It has ALL OF THE CHARTS FOR THE WORLD! And OpenCpn opens them just fine. Along with all other charts that I have tried to open.

Not sure how long the download sites stay good as I think they come and go.

One thing that is interesting with SeaClear is try to plot a course from, say Mexico to New Zealand, you can't do it in one course! You can't plot across the international date line. Also, SeaClear was done many years ago and has not been worked on since.

OpenCPN is currently being worked on by a number of people, so seems to work MUCH better. At least that's how I see it.

Greg