Tony,
Many of the hotel outdoor pools are heated to extend the season as long as possible. We've been down in October and November and either been in coats to simply tshirts. Weather truly varies, best idea is to check
www.weather.com a couple days prior to your visit. Ocean swimming again, temperatures vary but would be very likely, especially since the heat of August has warmed the ocean water dramatically.
Many places will still be open, the biggest change you will see is the outdoor rides will all be closed (they close the week after labor day). Otherwise, pretty much business as usual.
Thank you,
Anna G.