So the water in this game is basically 2 texture shader thingies which moves in the opposite direction of each other. It makes it seem as if the water is, well, water. To create an illusion of movement while riding the ferry, SE has tinkered with said water texture to make it seem as if though the ferry is moving ahead.

Here's a sophisticated rendition of the current water texture in the ferry instance. The length of the blue arrows represent the speed of which the water planes move in their respective directions.

http://i52.tinypic.com/yp3wo.png

As you can see, one of the texture planes is barely moving at all (It's actually moving in the SAME direction as the ferry is supposed to be moving! How was this overlooked? ). Which means the water will seem to be stationary. Which means we've found the culprit in this drama!

Solution:

http://i52.tinypic.com/29tv2x.png

It kind of frustrates me that this hasn't been "fixed" yet. I know you've got better things to do SE, but we're talking editing a texture or two. It would improve the ferry ride tenfold. Please try to squeeze this in with 1.17.