Here are some links to sites that are of interest to Swim the Apple:
Please feel free to suggest additional links; we will evaluate and include them if appropriate.

Working Waterfront Association
Floating Swimming Pools
New York Tide Chart
The Waterfront Project/Waterwire
Hudson River Watertrail Association
Downtown Boathouse
DEP Water Quality Survey
The River Project
Hudson Riverkeeper
Hudson River Foundation
New York League of Conservation Voters
Floating the Apple
New York Sailing and Racing
New York Waterway (ferries)
Ferry services in Port of New York
SeaAirNY seaplane tours
Governors Island
Manhattan Island Foundation
Waterfront photography by Carolina Salguero
How to visit Governors Natural Resources Defense Council
The Van Alen Institute
The Waterfront Center