Stratofins - Water Rocket

I found an interesting rocket website selling screw on water rocket fins and  launchers - HERE

I had seen StratoFins listed on the Apogee website. But like the rest of us, I thought the idea of a water rocket wouldn't be worthwhile.

From the Apogee website:
"Water rockets without fins are unstable. While they may be fun anyway, they have the equivalent power of a D motor. Therefore, they need fins to guide them in the straight-up direction. . . . they are made from a stiff, yet resilient plastic, so they are practically indestructible, even from a fall from 600 feet."

The videos are worth watching:
One video shows the flight and performance differences between launching a finned and no fin water rockets. Jolly Logic altimeters are on board and all the flight data is presented.
Another video shows how Quest adapted their model rocket launcher for water rocket use.

The Equivalent power of a D motor? 600 Feet from compressed air and water? 

I doubt it'll reach 600 feet. But, If engine prices keep going up I might end up flying these!