How to move the foam area for a foam generator in Unity

I’m trying to spawn a foam generator depending on whether the trigger object is near the water in my Unity game, but the object is outside of the foam area. I could move the trigger object within the bounds but if I move it outside of the foam area, the foam will disappear which I don’t want.

I was wondering if there’s a way to move the foam area when the object moves? Here is a screenshot to better explain the scenario:

Any help or advice with this would be much appreciated.

Thanks