Interesting discussion. Growing up in New Zealand as a teen, 35 years ago, we had a 3 jet boats in succession, the first was a 13'6" with single stage Hamilton jet with a 3L V6, my stepfater like it so much he went for a new 18' with a 351 Ford V8 driving a 3 stage jet, the 753. It had a 7 inch venturi and the bulk of the unit was outside the stern, 3 impellors turned in the same direction with stators inbetween to straighten the flow. I don't recall any problem with getting on plane, it did have a nose up altitude, and spun on a dime at high speed, while at low speeds it pivoted around the bow, very impressive at the time. No doubt due to the exit being about 3 feet from the back of the boat. I think it maxed out at about 45 to 48 mph. With the unit mounted so far back the engine was also right at the stern comparable to a stern drive installation.
Due to the commercial use we upgraded to a larger 21' with heavy duty hull, Ford 351, and the 10 inch 1031 single stage jet, it didn't have the speed, about 35 mph+ but it could dig itself out of a hole even when heavily laden. Again the engine was rear mounted as the impeller was external to the hull.
The attractive features were shallow water ability without snagging bottom, rocks etc, turn in it's own lenght maneuvuring, and being able to drive straight up onto the trailor, something I could do successfully from the first time as a teen. Line up, blimp the throttle, and you were up on the trailer as easy as. Towing skiers with the 18' presented no problem, not tried with the 21'.
Variable inlet and exit, variable pitch fan, do we need all this added complication. I'm reminded of the high tech Japan adds to it's cars to improve handling, eg, 4WD, 4WS, electronic damping, etc, while a good European car handled as well just with a well designed drive train. All the Japanese hybrids designed to increase gas milage (wait till the battery pack needs replacing) while Europe just designs more effecient diesels. Give me a jet unit that is sturdy, low maintainence, good proformance over a wide range even if a little down on what can be acheived with hi tech addons.
Oh, interesting site BTW. Love big boats
