Bring foulies just in case.
You are going to want to come up with a loose itinerary but if it were me:
Rough calculation: 18 nm Stamford CT to Throgg's Neck Bridge at 5 knots/hour should take about 3 1/2 hours.
High tide at the Battery: 04/26/2008 Sat 01:22PM, which means that by 2 hours after this time (Eldridge current charts
) the current in the East River will start flowing SW, so by around 3:20PM you will want to be in the East River.
Working this backward to Stamford you will want to get underway on Sat 4/26 around 10:00 AM to leave a margin of safety and if you want to sail for a bit, here and there, wind permitting. Leave even earlier if you want to try and sail all the way (I once sailed all the way to Hell Gate before firing up the motor). It is a bit like a flume ride by Roosevelt Island so you will want to power up before this so you can have some steerage way.
Spend the night at Liberty Landing or wherever.
On Sunday 4/27, the current in the Hudson starts flowing north 4 hours after low water at the Battery (Eldridge) which is predicted at 08:04AM, which means that the current will start going your way (north) at 12:00PM. So, leave before noon using the engine to fight the current and by noon or so you will be pushed up the river. You will want this following current when passing the Palisades which mostly block the usual SW wind. Nyack is about 25 miles upriver while Haverstraw is another 10 miles farther up, both decent places to stop for the night or just push on all the way to Poughkeepsie and pray you get there before dark. This could be a pretty long day but not impossible.
Watch out for barge/tug traffic on the Hudson.
It is a good idea to monitor ch. 13 in the East and Hudson rivers as mentioned.
Sounds like fun. Let us know how you make out.