Jack, if you look up the one in NYC
it was the site of the world's largest non-nuclear explosion, as the USArmy literally undermined about ten acres of river bottom and then brought the rest down with explosives to drop the river bed
deeper into solid rock. What remains today is nothing at all like what it was named for. (The old newspaper reports make interesting reading.)
Unbusted, Eldridge is the local bible for a HUGE section of the coast. The sailing directions (point to point) the local advertising and information, the current charts
for all of LI Sound as well as NY Harbor and the HG....You'll find that orange book on board every boat
in the area that does any kind of serious sailing. Using their advice to play the currents in LI Sound can save you many hours, especially in light winds.
You CAN use the current charts
(which are published by NOAA) and just offset them from the tide times posted in any local newspaper, but the book itself is handy. I can't say I've ever heard anyone say it was money
wasted,and the charts can be used year after year, as long as you have tide information to time them off of.
Or, you can hang out until you see traffic heading up river, it tends to get busy in time for the slacks. And someone should have a copy you can look at, in every marina and dockmaster's shack.
Of course ideally the USCG should be able to tell you the slack on any given day...but sometimes, they get plain nuts and refuse to provide information like that, which somehow could endanger you. (Honest. Go figure.)