Pretty interesting to see the water ballast systems start to show up in smaller recreational boat hulls. Moesly designed the 25 seafari for one back in the late 60's. Around the same time Raymond Hunt was building a water ballast system (during his retirement years) in a Hiliner hull.
http://www.maineboats.com/ray-hunt-yacht-designer
Now they seem to be popping up everywhere from wake boarding boats to fishing boats.
https://www.youtube.com/watch?v=CF9_-q4TbF8
https://www.barcrusher.com.au/technology/bar-flap/
http://www.boats.com/reviews/enzo-24...line-tow-boat/