Obviously a permanent type of attraction like this, that runs on a track, willbe expensive - although would fit perfectly in the lake. However, I discovered that floating versions of the ride exist which lower the cost and get rid of the need for a track.
I think something like this would be perfect for PWH!
I too have thought a Splash Battle would be good for the lake, themed one would be good, as there's too many of them generic ones with the red and yellow boats.
I don't like the look of this floating model - permanent installations are the only way PWH can improve. Andyb's right though we just don't have the climate for this!