Good question. It's definitely not turqoise water like in the Keys. The answer can be very subjective depending on who you're talking to, but id you want to stick to the facts, go to the site of the Department of Environmental Protection . You should also know that New Yorkers have been holding the annual Manhattan Island Swimming marathon for years now, and the swimmers seem to come out of it without green or purple appendages...I've personally been swimming in the Hudson several times and I found it just fine.

One of the things we do caution for at the skippers' meeting is to watch for driftwood, especially in the harbor. Stories about dead bodies floating on the water on other hand are somewhat exaggerated or date back from the 1980's