Amphibious ATV Jet propulsion systems?

[beungood]

Take a look at the new Amphibious Assault vehicle the Marines are using. Thier new design actually allows the vehicle to get up on plain with the use of retractable planing devices.

[lewis]

Marine Amphib

The tracks are also retracted and a smooth hull is in the water and this is all done automatically and a bow plate is lowered to help it get up out of the water, pretty good design. I think they can reach a speed of about 40 mph. Massive get pumps are the propulsion system.

[pmiller]

Jet System

Our earlier version of the Land Tamer offered the Jet System as a accessory. We moved away from this option because it is not as efficient as our new hydraulic propulsion system which pushes the LT thought the water at 5 mph. The Jet system was a slick setup and was built right inside the hull.

[LarryW]

I have thought of putting a 90 degree gearbox under the motor with a shaft running out the back. Exactly like an axle only spinning faster. With axle bearings. Then making a removable propeller, just like a wheel hub. Then having a rutter like thing behind it to steer. The key is making it removable so it is not damaged in rough mudding or other more "land" like terrians.
It is not a jet pump but sounds like it would be easy to do. Seems like it would work but that is the question? Just sharing ideas.

I was really looking into putting a jet pump into a little row boat I have. There was a forum on doing such things. It seems it took alot of motor to move the boat with any speed. And the boats dont have wheels draggin. They used old jet ski motor and pumps. They also said it wouldnt go in shallow water at all. There was something with placing the pump where it wouldnt suck air or cavitate. Maybe there is a better way though. You could find a site like that and might help answer some questions on the mods and such. Like what pumps work better or what ever.
I would love to hear of someone doing such a mod to improve water speed.

[6X6]

Hi:
Jet pumps ARE less efficient than propellers, by quite a bit, but less prone to damage. (And also MUCH safer if a rider falls overboard) This is why we see props on cruisers and high performance craft, and jet pumps on jet-skis, PWCs and "skinny water" craft. (yes, there are high-performance jet boats as well, they just need more motor for the amount of go). They can take sucking up sand, mud and pebbles. If you don't believe me, watch any of the youtube videos of guys running their boats up streams/brooks skipping their hulls off the bottom in 4-6" inches of water! (As a boater myself, I always make sure to keep the outdrive OFF the bottom, and these videos still make me cringe!) The enemy of a jet pump is rope and heavy weeds (And in an AATV's case, vines). It will foul a prop as well, but thats much easier to get off! Larry, I like the removable prop idea, but if it's below the tub, the shaft will still be vulnerable, if its directly behind the tub, the prop will be quite inefficient, and if it sticks back a bit, the shaft may still be vulnerable while backing up, going over logs (Don't you like to do that?), and starting up a hill/going through a ditch. Maybe a removable prop/outter shaft? I would personally go with the jet pump, but a high flow water or waste pump may work pretty well. (If the jet pump design pushed so much more water, I think many industrial pumps that don't have to be self-priming would use that design, but I don't know enough about them to know why/ why not)