score:5
According to this 2015 Ynet article (Hebrew), Lockers were placed in most Tel Aviv beaches.
A locker is opened with a 10 ILS coin, which is not returned.
The official visit-tlv site has a beaches section in Hebrew, which says which beaches have lockers. The lists differs from Ynet's, and I don't know which is correct.
Beaches which have lockers according to either list: