Here's a video demonstration...
http://www.putfile.com/media.php?n=HydroFoam
Now you too can have one.
Free Plans For The Hydro Plane [RCGroups.com]
http://www.rcgroups.com/forums/showthread.php?t=380781
P.S
Please bear in mind that the last link incorporating plans for the Hydro Plan are not the originals. If you can wait, complete kits and official plans are due to be released soon. Check the links above for more details.
ZeroP