[Public-List] Diesel conversion

[John Riley]

jon wrote:
>  to go through the Dodd Narrows against a six knot min imum current.
>

I see this kind of comment all the time, and I am genuinely curious.

If my 8 HP outboard can push the boat at hull speed (a touch over 6
knots) through the water, isn't that "adequate" by any practical
definition (wait, I'm not conflating outboard HP with diesel HP).  Hull
speed is hull speed once I reach it, and my speed over ground is
determined by the current, not the HP of my mechanical propulsion.

I've motored into a 25 knot headwind against a 2-3 knot tidal
current...with a speed over ground (as measured by GPS) a touch over 3
knots.  That seems about right to me for making hull speed (or near
enough), so I'm failing to understand how extra horsepower would have
made any difference.

I do concede the point that bigger winds may demand more HP; but speed
through the water is the same whether the water is moving or not.

And finally, does Dodd Narrows have that flow ALL the time?  No Slack
Water, no Flood/Ebb cycle?

-- 
John S. Riley
S/V Gaelic Sea
1972 Alberg 30 #521


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