I've chartered a Jeanneau 37 from TMM in the BVI, as well as numerous
Beneteaus from various companies in various places. I didn't use the
quarterberth on the Jeanneau for anything other than storage, but I
don't recall there being an operable hatch. It's been a few years,
though, so memory may not serve. We used the v-berth, and I don't
recall there being any ventilation issues. We did, however, use a wind
sock on the hatch.

The Jeanneau sailed better than most of the Beneteaus I've chartered,
probably in large part because its sails were quite fresh and its
bottom clean. In my experience, there's more difference boat to boat
within a brand/charter company than there is from brand to brand--at
least among the typical Caribbean fleet. Now the Sabre 34 I've
chartered from Whittaker Creek in Oriental, NC--well, that's a
different matter.

David