Our unit studies are like Lorel's... More seat-of-your-pants tangents rather than anything planned in advance. Sometimes it's interest-led and sometimes just kismet -- we had a weekend in Gettysburg that turned into a big long email discussion between DS and my dad and has moved on from the Civil War to "necessity is the mother of invention" and the mixed bag that is technological advancement.
I've not tried to link everything, but everything sort of comes up. They're currently on navigation and Bowditch and there's plenty of geometry inherent in that... and of course history and geography, and DS is reading
Carry On Mr. Bowditch and thumbing through the
American Practical Navigator. If I get around to recording it as schoolwork it will all go under history. We're still doing other math, and other science (and other history and literature for that matter) -- it's just a side thing that feeds his particular interest in the topic, and while I do make sure to give him time to pursue it, I'm not really involved beyond supplying the books
We get a lot of mileage out of wikipedia and its recommended links.
