Hi Donald,
That's just not true. 5HP cannot not push a 10,000 pound sailboat with a 25LWL, more specifically a Catalina 30, to hull speed. And suggesting that it would be possible with a 12,000 lb Catalina 34 or 13,500 lb Catalina 36 (there is no Catalina 35) is horribly misleading.
A 5HP motor will move the boat around, better in calm conditions than in heavier winds, but you will not hit hull speed. A Catalina 30 requires about 300 lbs of thrust to hit 6.7kts and a 5HP motor or engine, inboard or outboard, doesn't come close.
We've observed many times in this group that 1kW of power per ton will push an auxiliary sailboat (all sorts of designs) to about 90% of hull speed. That last 10% will come close to doubling the power demand.
So I can say that it has been proven that it takes at least 6.7HP (5kW) to push a Catalina 30 at 6kts in calm conditions, often requiring more power if the drive isn't really efficient, like your traditional outboard driveleg and propeller. It has been my personal experience that the Torqeedo outboards are much more efficient than traditional outboards, putting them close to the same efficiencies as many electric inboard installations, but the Parsun or Ray Electric will not deliver the same range for a given speed. And one of my main objectives has been to get the maximum range for given speed from the same batteries. Perhaps other people have other priorities....
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@yahoogroups.com, donald bland <dlblandjr@...> wrote:
>
> You can easily push a catalina 30 or even 35 to hull speed with 5 hp...
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