Turk, it is the currents and not the tides you will have to worry about. Tide is the vertical movement of the water
and just affects depth
(which you'll have plenty of) and the associated "sideways" movement of the water
. Which is a problem in the East River.
I hope you are not planning to go UP the East River to join the Hudson
, you must go down to the Battery
and around Manhattan. The bridge clearances/openings on the north part of the East River are essentially impossible for sailboats.
A copy of Eldridge, the yellow/orange colored book available in any local chandlery
, will give you tide and current
information for the whole trip, along with a lot of other good information.