There are homes in Rockaway which are occupied full time and if you live in one you are considered a "local."
There are homes in Rockaway which are occupied part time and if you live in one you are considered a "weekender."
I have recently noted there are homes which are only occupied during the major beach holidays: July 4th, Labor Day Weekend and New Year's Eve (with a nod to Memorial Day). Interestingly. these houses are not usually inhabited on any other weekend throughout the whole year. When they are occupied though they are full to the brim and then some--several big cars parked in front, tents and picnic tables outside, kids frolicking and fire pit revelry all day and into the night.
I am not sure what locals call them, but I suggest "holiday houses." They make our little community come alive and even the houses themselves seem to proudly beam with joy.