Interesting Jet Drive Patent

[Doc Nozzle]

Is anyone familiar with this patent - 5910032 issued in 1997 to Brunswick Corp? I am curious if the features claimed in this patent have ever made it into any real applications. When I study this patent, the key features that I interpret are:

a) Unique inlet gullet configuration - where the overall length is greater than "conventional" jet inlets.

b) Inlet is divergent first, then slightly convergent.

c) Nozzle exit area to impeller effective area ratios are much greater than either Hamilton or Berkeley.

d) Fig 12 is the most interesting (for me) - the two curves at the bottom #350 & #352 are very close, if not identical to typical performance for Hamilton/Berkeley style pumps. My understanding is this patent is claiming that it's design improvements can increase Mdot/Power In by 2X-5X.

I always want to hope that there are still "huge, secret" gains yet to be discovered, but this strikes me as on the borderline of hard to believe.