Hi Michael,
Imagination is one thing, reality is often something else.
Jet pumps are notoriously inefficient. Even for boats that have plenty of horsepower available (not electric), very few use jet drive unless the power to weight ratio of the boat is really high (think ski boats or tugs). The few prototype electric jet skis don't seem to have been able to resolve the jet pump efficiency problem well.
Rudders on the floats are discussed regularly amongst F-boat owners, and pretty much all of us, including the designer, Ian Farrier believe that they aren't worth the extra trouble unless you are regularly flying the main hull like Oracle's Dogzilla in the last America's Cup. On normal trimarans, the linkages are too fiddly and the added wetted area (drag) comes without an increase in manueuverability or stability. The few people that have gone through the effort andd expense to install them have switched back at their next re-fit. Of course, if you have successfully added rudders to the floats on your trimaran, I would love to see how they turned out and what kind of performance increases that you experienced after installing them.
I am about to replace the stock rudder assembly on my F-27 trimaran with a high aspect ratio dagger-style rudder, that should take about 60 pounds of the stern of my boat while reducing drag and improving the handling of the boat.
Fair winds,
Eric
1964 Bermuda 30 ketch, 5.5kW Propulsion Marine drive, 8kWh Lithium batteries
1990 F-27F trimaran #167 Witchcraft (with a 4-stroke outboard in the well)
Marina del Rey, CA
--- In electricboats@yahoogroups.com, "Michael" <mwfleming2012@...> wrote:
>
> OK, with all the considerations of efficiency, and particularly of those with trimarans, have you considered some, although major, modifications to a simple, yet beaching friendly, jet pump? Change to kick up rudders on the amas and delete the outboard and massive rudder on that beautiful stern. Let your imagination take care of the rest.
>
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