Larger beach properties are typically divided into zones, indicated with a ZN-xx designation, for ease of inspection and maintenance. These zones are sometimes further divided into sections for a particular street or beach segment, and it is those smaller sections that are depicted in this dataset.
This dataset uses the standard NYC projection of NAD_1983_StatePlane_New_York_Long_Island_FIPS_3104_Feet. Lengths are in feet and areas in square feet.
Data Dictionary: https://docs.google.com/spreadsheets/d/1YwneNR7WwLh5jZiI69LXWuW6yegeVo6HdiTpKTjI0tA/edit?usp=sharing