Note: Before attemping to kayak the Hudson, make sure you review the tidal charts first. The Hudson River, even in Albany, can have very strong currents either heading north or south, depending on the tide.
The river increases and drops on average of 5 feet per change of the tide, with the strongest currents at roughly 3 hours after the last tide change. Expect especially strong currents around that time. And do not expect to be able to easily paddle against the tide. When the tide is going out, and water levels are dropping, the river pulls strongly to the south, when the tide is coming in, the river pulls to the north.