The Hudson River side is much worse as that is the side with all of the Cruise Ships, the barges, freighters and tankers going up state and as bad if not worse currents during tide change. Being much wider than the East River, the wind can cause more interesting wave action on top of everything else.
In order to operate a Seaplane in the East River legally, you have to get a certification / endorsement.
There had been a Seaplane Base on the Hudson in Peekskill, New York for years, but that was in a protected natural harbor. It has been closed for a long time.
Skimmer one can comment on seaplane operations on the Hudson River, South of Albany, where one day it is safe and another it can be treacherous.
Both the East River and the Hudson are pretty much salt water around Manhattan and brackish for the first 50 miles as well as tidal.
Once you get up North of Albany, the river is much more forgiving, narrower, smaller boat traffic, no tides and no salt.
When I am in Chapel Hill and the surrounding area, I have noticed some quite large lakes, that maybe resevors too. Can you operate on any of these near Chapel Hill?
SUPPORTING MEMBERBobWest Nyack Aviation, L.L.C. New York, New York - East Hampton, New York & Warwick, New York firstname.lastname@example.org