Scorer75... c'mon, man. I can understand being cautious, but you're cycling in one of the most populated parts of the world. I'd be openly shocked if you were more than 30 minutes (by bike) from water at any point on that ride. Heck, start out with 2 bottles and you could easily make it from the GWB to Piermont without running out.
Seriously, there is absolutely no reason to worry about getting water or liquids on that ride.

Wow - when I went up to Nyack earlier this year I had two bottles (one gatorade) and two liters on my back, temps in the 70's. Emptied it all before I got to Piermont and almost emptied them before getting back....
Different riders need different amounts of water/liquid when cycling. For example, I only need 20 oz of liquid per hour in 80 degree weather.
It's pretty easy to figure out.
1) weigh yourself before a ride
2a) do a 1-hour ride without drinking, or
2b) keep precise track of how much you drink during the ride
3) weigh yourself after the ride
4) figure out how much weight you've lost during the ride, and convert that into ounces. If using 2b) you will want to subtract the amount you drank from your final weight.
Also, slvoid is rather fast, so it probably takes him a lot less time to get to Nyack than you or I.