I fish the gates often.
The locks close 3 1/2 hours before the high tide at Sandy Hook, NJ
They open 2 1/2 hours after the same tide at Sandy Hook, NJ..
To the minute, you can almost set your clock to it.
good luck, summer brings out too much boat traffic though, permits available for night parking, which I highly recommend this time of year. seems quite a few boaters don't understand the tide and start stacking up for a manual opening and it gets to be a zoo sometimes.
Much nicer in the early spring and fall with decreased boat traffic. These days though, it's a night game for sure until they start shrink wrapping those boats again.
If you need more info feel free to pm me, no problem.