[Rhodes22-list] Measured Hull Speed

[Christine Allison]

> How do you people plan your trips if you don't know what fuel mileage to
> expect?  This is pretty fundamental stuff.>

Might I modify this to read  "steaming endurance."  Around here, in salt
water there are currents, some times very significant.  These currents can
accelerate you or bring you to a practical standstill.   Unless you have a
publication with the proper current direction and velocity charts and use
them to work out your approximate passage time you may find yourself out of
fuel which under some circumstances might be highly embarrassing.

I am not advocating any elaborate calculations but to give an example;
Around here (New York City) we use the Eldridge guide.  It contains current
charts for Long Island Sound.  The chart to use is keyed to start of the
current set at the Race (easterly entrance to the Sound).  Given your known
through the water velocity and always assuming the current is dead on the
bow or stern it's easy to figure out the mileage made good at hourly
intervals.  Add a little extra for eventualities and there you are!.

On an expected 6 to 8 hour passage I always add another hour to allow for
the unforeseen.

On any significant passage I carry fuel equal to 150% of the expected
transit time.

Richard Smith