Calvert is a good system. I know of a couple families that use it, or have used it and they seem happy with it. We looked into it, but ended up not going that
route for 2 primary reasons: 1. Calvert doesn't incorporate the cool places you'll be into the curriculum, which to us was
lost opportunity (culture/history/geography/etc). 2. Three
children using Calvert, "school in a box", all had very different materials/subjects, making the teaching burden much harder. In much of
learning, our
kids can study the same topics, but at different levels of complexity depending on their age/grade/ability.
Almost all of the cruising families we know have their own slant to
boat school - and it takes a little time and willingness to
experiment, to figure out what works for you. PM me if you have more questions.