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Re: outboard




Bob Schimmel wrote:

>A displacement hull never gets up on the step as power is applied.

>However, if you push the hull to its theoretical limits, 6 knots for a
>SJ23....
>...To push it faster than that
>and it requires a significant amount of extra power...

Yes, that's as I understand it. So, if it's true that a 5 hp outboard will
push the SJ23 to 6 knots, its hull/maximum speed, then what reason is there
to have more than that? I keep having the feeling that many people think
they can overcome this handicap by adding more power, but that's not true,
as I understand it.

>Please keep in mind that this discussion centers around efficient speed
>through
>the water, NOT ground speed over the bottom.

Yes, just as with an airplane. If you are making 6 knots/hull speed through
the water, with a 7 knot current dead on the bow, you are going backward 1
knot over the ground and being washed out to sea. It is my understanding
that you can't solve this problem by adding horsepower, because you can go
no faster than hull speed regardless of the size of your motor. So, the
reason for my original question... how big an outboard does it take to
drive the SJ23 to its hull speed? I don't ever want to get caught in a
situation where a little more power would get me out of serious trouble,
but I don't have it. How much do I really need, how much can I really use?

How does the wind fit into this situation? If I'm on a lake with no
current, but I need to drive straight into a hard wind using the outboard,
will a bigger motor make that easier to do? A bigger motor can't overcome
the water resistance which limits us to hull speed, but can it drive the
boat into a strong wind where a smaller motor could not?

Bob






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