I think that this is the general direction I will try first. One of the things that occurred to me during this conversation is that the most likely historical query would be to pick a ship and plot its track over time. I don't think I would ever query by a geographical location (lat/long box or circle search) ever. That doesn't make any sense to me (at least right now. If I have to do it later, I could always just dump the file into a DB and query it that way.

I like the idea of being able to trim the historical data by ship/date, because I don't have to trim all ships to the same period.