Actually it does seem to have some good functionality on the East coast. For example, a challenging passage for a trawler from NYC to Long Island sound is going through a section called "Hell Gate". It's a narrow section of the East river between Roosevelt Island and Rikers Island and for a trawler, it really helps to try to hit Hell Gate at or near slack. If not on slack, you want the current pushing you through (mostly so you don't spend a lot of time tangling with commercial vessels).
Anyway if you look at Hell Gate zoomed in on Deepzoom, it gives an excellent graphic of the timing of the current. It's a little tricky to time this because current variations start way back at the Brooklyn bridge.