Since you are saying "vacation" and "short trip", I assume ease of access will play a part of decision making. If you need to fly to the destination, proximity and ease of access to an airport becomes a consideration.
Coastal towns north of West Palm Beach, Florida would fit your criteria and provide ease of access. PBI airport is large enough to provide ample flights, and small enough to easily navigate. Located near I-95, head north to one of the coastal towns that provide the recreational activities to match your preferences.
The further north you go, prices may become more affordable. Consider Stuart, Jensen Beach, Port St. Lucie, and further north, one of my favorites, Vero Beach.
When you want to pick up the pace from the beach, Palm Beach County is within a reasonable drive with plenty of options to keep you busy.
On the gulf side, check out beach towns surrounding Sarasota or Tampa, for similar reasons. The airports provide ease of access, frequent flights, and you can have laid back beach days mixed with the activities of a few cities nearby.
Deborah Madey - Broker
Licensed in NJ and FL