Click to see the picture much larger
Depending on how fast the water is moving you can keep playing around with somewhat slow shutter speeds.
I love the look of water in the 1/30th to the 1 second range it gives it a great sense of motion before getting to that silky smooth look which is also great but different.
This was taken at 1/4th of a second
One of the great benefits of a Nikon D850/810 is getting the 64ISO or even the 32ISO-Low so that you can get some slow motion stuff even when there's a decent amount of light out and you don't have to be carrying a ND filter.
I took this last weekend in Florida the morning before getting on a cruise... more about that soon.