Plyometrics, as we have discussed numerous times, are great for developing power and quickness. They are also serious work for joints and why most coaches recommend you have some serious weight training under your belt before you begin a serious plyomterics program.
People have often hypothesized that one could develop similar levels of explosive force with reduced impact working in the water.
Donoghue, et al; 2011 compared aquatic plyometrics to land based ones. 18 male swimmers on the university swim team participated. They completed a series of ankle hops, countermovement jumps, tuck jumps, single leg vertical jump and drop jumps.
Peak impact force/BW was reduced by 33-54% in the water. Landing impulse was reduced by 19-54%. Rate of force development was reduced by 33-62%. Ground reaction forces were slower for countermovement jumps and tuck jumps while earlier for single leg vertical jumps.
Given these numbers, competitive and high level athletes must continue their pre-season plyometrics on land. Their off season or post-season training could be integrated to include aquatic plyometrics where overall power and quickness are not called for. Also, non-elite athletes could definitely start their plyometric training off this way to get used to how plyometrics feel and what changes they can generate in the body. This is an interesting development and one we will watch.