Liberty Harbor Path?

Here is link to the PATH.PATH information
Memory serves me that it is about 5 blocks north and one block east to the Exchange Station from Liberty Harbor RV park.

PATH drops you off at World Trade Center or 34th St. Grove St station may be a little closer to Liberty Harbor. Never noticed a honey wagon but there is a dump station.

The path takes you to the 911 memorial. We did it twice. However we liked the ferry. Much more scenic, but there is walking involved. If it's a nice day it's not bad. The path however gives you a transfer so you can take the NYC subway to Times Square.
The ferry to liberty island and the Statue of Liberty is also right there. You do have to take a ferry across the harbor to get to it, I think it's $3 to board and cross to the other side.
If your not at your RV all day the gray tank should last you a few days depending on the size of your tank. I don't belive there is a honey wagon, but they do have a dump station.

Here was the view from our spot!

The Grove St PATH station is 0.6 miles from Liberty Harbor RV Park and is a quick walk even if you aren't in great shape. Using Google Maps, it says that it is a 12 minute walk, but I don't really remember it taking that long. It was less than 10 minutes for us with 2 kids between 5-8 years old. We were in our 50s and DH has had back problems for years.

The water taxi over to Wall St runs ONLY Monday - Friday during work hours and is $8/per person ($7.50 for sr) and that is one way. That was just a bit too steep for us, so we walked the .6 miles.

While we were there, we saw several people getting taxis to go to the station. I have no idea how much that was, but figured it was too expensive for us.

If you are wanting to be close to all that the NYC has to offer and don't care to have a "camping" experience, Liberty Harbor is the place for you to spend a few nights.