Ryan Cabanas wrote:
I've seen these many times before and I have no idea what they are.

I live in Manhattan and I was walking along the Hudson and I saw these
wooden poles randomly sticking up out of the water. They were various
heights and they didn't seem to be doing anything. When I rode the
Staten Island Ferry over to Staten Island, when the ferry pulled up to
dock, I noticed a very large amount of these poles right by the docking
area, as well.

What are these poles for? Thanks.

Ryan Cabanas

As many have answered, most likely pilings from old piers, docks,
structures. They are not unique to the Hudson River. Got watch for
the old Berkeley pier pilings, among others when navigating SF bay.
There are numerous such hazards out in the CA delta too.