For those who may not be familiar with Blue Point:
Blue Point is a hamlet (an unincorporated area) in the southwest part of the Town of Brookhaven, in the south-center part of Suffolk County, along the Brookhaven/Islip town line.
Beginning on the north and moving in a clockwise direction, the Hamlet of Blue Point in the Town of Brookhaven is bordered on the north by the Hamlet of North Patchogue; on the east by the Village of Patchogue and the Great South Bay; on the south by the Great South Bay; and, on the west by the Hamlet of Bayport in the Town of Islip (the Brookhaven/Islip town line).
The Hamlet of Blue Point has a different border than does the "Blue Point, NY 11715" ZIP Code postal zone (i.e., a place can have a "Blue Point, NY 11715" mailing address and not be in the Hamlet of Blue Point): places that have a "Blue Point, NY 11715" mailing address that are not in the Hamlet of Blue Point are in the Village of Patchogue.
For a good set of town-by-town maps showing all the villages and hamlets in each of LI's 13 towns (3 in Nassau County and 10 in Suffolk County):
Excellent Long Island Geographic Resource