Schooling and cruising.
Well, we did have a year when we did more or less the same - but generally on land. And it was all a couple of decades ago. We went around the world (about 20 countries) over a year when they were 6 & y/o. We organised and began to try the government school
(free) distance education system.
After a few months we simply gave up and let the experience be the educator. The key problem was that it was very labour intensive - one parent per child for half a day. And there was considerable "client" resistance! Several months of this were in a motorhome in Europe
, but keeping a working schedule was difficult. I imagine cruising would create similar issues. So they barely attended school
for a whole year. There was a short period in Denmark
& UK whre they went to the local government
school (in both cases fror free!). But this was mainly for social reasons.
But, based on the educational/academic outcomes for both (degrees, etc), it certainly didn't harm them. The life experience - a variety of people, places, experiences was very educational. Gee, they even began to learn Danish - now there's a feat!
There were "moments", but a couple of funny
scenes. In a modern (Dutch) art gallery my 8y/o son commented that "If I painted like that my teacher would just say I'm messy". (2) in Paris he also tried out his French by asking "Une baguette, s'il vous plait" and was rewarded with a sale! Then (3) the same 8y/o set about designing a huge vacuum system which would extract the incredible pollution from an eastern European city. But then there was the time in Prague when they both refused to visit one more cathedral!
While I would try to keep up the reading, and a few basics, I'm not sure I would worry too much if its just for a limited time. Surely there is lots to be learnt in the line of geography, physics, even maths from living on a boat, not to mention self confidence and social skills.