The dinghy dock is still under construction, but a new place has opened in Playland Park, Rye, N.Y., called Pier Restaurant & Tiki Bar
It's on the site of the old Captain Hook fast-food joint, but much enlarged. Run by proprietors of Seaside Johnny's in neighboring Oakland Beach, Rye.
The dinghy dock will be on the south side of the old steamboat pier, on the side that faces the swimming beach. Looks like Playland Park management has removed the six mooring balls it had put in (and never maintained) many years ago, which were on the north side of the pier.
Edit: Dinghy dock now reportedly completed. See new post further on in thread.
Write-up from local paper is here