Found some interesting vids of old Russian shallow water water-jet passenger vessels, which use some very old tech, pump units. They divert water either backwards for forward movement, or through side ducts near the transom for reverse, very similar to an old steam water pump vessel someone mentioned a while back. These vessels were used to service river villages where no other boats could go. They are powered with a V12 diesel of around 1000hp (similar to the motors in the old 'Kometa' hydrofoils) and get up and plane on the almost flat hull (with a tri-hull entry). This one is from 1964 and has been recently, privately been brought back into service, due to the govt cancelling the previous service performed by a newer boat, (along with many other crucial passenger ferry services across Russia)
This water-jet system is also used by KC 100A log raft working launches which are powered by a V8 diesel of around 100hp. Very unusual interesting vintage boats, which are still used. I guess the Russians have the thought that "if it ain't broke, don't fix it" Most of these boats have pneumatic systems for shifting the jet controls, as they will work in frozen conditions, (you can hear it working in the vid with the 2 guys) -same as the old YAK training aircraft use for landing gear, brakes etc. Quite cool,- (think some of the hydrofoils use pneumatics for various controls as well.) The one the 2 guys re-built does around 30kph flat out, as they have done a few mods to the hull, (big spray rails for more lift etc). These Russians seem to have lots of fun with all these old boats (and trucks etc), must be cheap to purchase.
And lastly, for those of you who might love the sound of 6000HPs'worth of MTUs pushing an ex Russian Kometa hydofoil at around 35 knots in Greece, - I give you,----