After I play the whistle on a screen with the Whistle -> Dry Lake Screen Data Flag, Link is able to walk on water, but only for a few seconds. After a few seconds, Link will fall in the water and get stuck, and all you can do is dive in the spot where you fell.
Note: This seems to be happening when I have the flippers. Because Link never get stuck when I don't have the flippers.
Whistle -> Dry Lake Bug
The issue here is that the lake doesn't dry immediately - as in the NES, there is an 88 frame delay. If Link goes wading in deep water during that time, he'll become stuck as the lake solidifies - realistic, I suppose, but not very desirable. Fixed in the next build.