Having bought a couple of them just for giggles, i can tell you that most of them are small scale charts on the order of 1:125,000 or smaller. Good for a general look see or passage
making but nothing detailed. You do get a few large scale maps of harbours and what not but every harbour. The other thing is the age of the charts.
Each one came with basic viewing software
on the disk, and it works well on my pc. I run a PIV with windows XP. Its fun to play with on a cold winter nite, thinking about all the places I'd like to see.