About Cherry Walk and W104th
This is just an access point for swimming in the Hudson River. The river is really accessible all along Cherry Walk.
However, for those who do not study it, prepare for it or ignore obvious dangers, swimming in this river can be life-threatening. The currents change minute by minute and can be very fast. You must be comfortable with open water swimming. It is very easy to panic. A small problem on land can be a major problem in the water.
Reasons to like it:
(A) its very recognizable due to the tree stump with a piece of wrought iron fence that insures it will be there for a long time. The tree stump makes a comfortable seat. Lately there's a very comfortable milk crate. Sitting on the rocks feels good when they are warm but they may abrade your swimwear..
(B) Its far enough north that when swimming in an ebb pushing you south you can still get out at rip rap between there and 100th.
(C) its far enough north to give you a slight core warmup from jogging there.
(D) the rip rap forms steps to get in and out.
(E) Its a concrete block that juts out into the river so you don't have to navigate rip rap to get to the water.
(F) there are good skinny trees and highway signs to lock a bike to.
(G) Its relatively close to Riverside Drive.
Others don't like the area of the stump because your stuff is not so hidden and its further from parking than say 100th.
Getting here by car. While you can walk, jog or bike here, you might also drive to a small parking lot around 98th (just north of the Riverside Tennis Clay Courts) and you might get to it by traveling north on the West Side Highway and bearing off at 96th to go south. You might find parking on Riverside Drive or one of the neighboring side streets.
Views. The views are generally bucolic. You will mostly see trees with buildings in the distance and joggers and bicyclists going each way on Cherry Walk. In New Jersey, there are more trees and buildings. Occasionally interesting ships pass by in addition to the more typical cabin cruisers and tugboats pushing immense barges. Unfortunately, there is a highway (the West Side Highway or Henry Hutchinson Highway) running along the river so there will be car noise including the possibility of sirens and motorcycle exhaust.
Bathrooms. There are bathrooms but they aren't so close. There are year-round bathrooms at the 102nd Field House but I went there recently and the door was locked. There are bathrooms open in summer only at Ellington in the Park. I imagine there are bathrooms at the Riverside Clay Tennis Courts but I've never checked them out.
Changing Facilities. None, other than the bathrooms.
Lifeguards. None.
Major Issues. The major issues are (A) current, (B) water and air temperature and (C) jet skis. (D) Cross Hudson excursions are a bad idea as that would involve crossing an active shipping channel. (E) Pollution. Its generally good to wait a few days after a rain before entering the water. The question becomes how much rain. This is a difficult call. While Manhattan relies on combined sewer outfalls (CSOs) to kick in when a wastewater treatment plant cannot handle the volume, Manhattan has very little landmass so it takes a lot of rain before the CSOs kick in. There's also a question of how much debris is in the water and what kind. After a rain there will be highway runoff which many might find a turnoff. Tree debris is ok if not too much. Dead fish are undesirable but rare. Usually the water is so clear that its impossible to tell if there's current unless you get in.
If you are a strong swimmer the current may not matter much to you, but you better gain some experience with it and while you may consider yourself to be a strong swimmer you may not be able to outswim the current. Water temperature varies with the season. Weaker swimmers should time their entry to when there is no current or very little current. There is a slack period happening four times each day. Only experience can tell you when that slack occurs.
After June 1 and until Oct 15, you are not likely to need a wetsuit for 15 minutes in the water. Air temperature will vary daily. Sun on the rip rap feels awfully good.