Well done...and it's given me ideas for our boat, where leecloths are not yet installed (but we have more traditional pilot berths).
Our son is now 9 years old, but when he was that age, we opened up an entire Groco play pen on our 33 footer and more or less jammed it in the V-berth. In a big sea, it could move, but didn't, as we didn't see big seas when we typically sailed with him. We could have lashed the playpen to keep it still, however, and "freeing" him was just a matter of pulling the playpen back about a foot.
Later, when he was walking, we would put up lifeline netting on cup hooks. This ticked him off a bit. After two, he was allowed the run of the boat, but wearing a little PFD
and always clipped on in the cockpit
, which he never left while underway.
By age four, he could swim and was allowed on deck
, and down below without while underway. This rule
continues to the current