Skip Gundlach wrote:
snip
Practical concerns have to do with our leaving the boat, as well as
entry/departure from various foreign countries, assuming we ever do
something different than cruise the US (we had expected to start in
the Bahamas and work our way south, spending, essentially, the rest of
our lives in the Eastern Caribbean).

There is a problem for animals in almost all English colonies - I no
longer remember exactly which ones.

These are the concerns we see:

Leaving the boat, whether for a day trip, or for an extended period,
even with cats being pretty self-reliant, would be a problem in that
we'd have to close up the boat, which, in hot climates, could be
deadly over time, inside heat building as it would.

Friends have got iron bars welded across the hatches, and this would
prevent people coming in and allowed them to leave the hatches open
for air when they were just going to be away for the day.