Scotty's boat has an LWL of 25 so 5 knots means an S/L of 1.0. Pushing a boat
at S/L of 1.0 needs one HP per 1200 pounds, which for 7500 pounds is 6.25.
Assuming 0.055 gal/hp/hour means about .35 gal/hour or about 35 hours run time.
At 5 knots, that should give him a range of 175 miles.

If you look at the specs of the 2GM20, these numbers are close to realistic,
though there are variables not considered, such has the propeller setup, and the
cleanliness of the hull.

So in theory, there should be no problem. If his only concern is no wind, then
he should be able to come close to these idealized numbers, or even do better by
slowing down some. However, if headwinds are a problem,or if the is absolutely
no alternative source of fuel, he might want to carry a reserve, especially
since he can gain 50% capacity with a low cost jug lashed on deck.


"Donal" wrote in message
...

"Jeff Morris" wrote in message
...
"Donal" wrote in message
...

"Scott Vernon" wrote in message
...

"Donal" wrote

I have done 75 miles using about 7 European gallons on flat calm.


Doesn't help any, Donut. Where am I going to find Euro gallons over
here?

You must have missed the bit where I said that US gallons were about 90%
of
UK gallons.

Your 12 gallons are about 10.8 of my gallons. Therefore, my opinion is
that
12 gallons will be fine as long as you don't try to motor into strong
head
winds.

I didn't mean to embarrass you .. honestly ... I wasn't aware that you
were
mathematically challenged!!

You're not much better, Donal.

Correct ... but I deliver my insults with more panache!

12 US gallons are under 10 Imperial Gallons.

Again, You are absolutely correct. I hadn't realised that US gallons were
so small.



Now that we have the confessions out of the way, do you think that Scotty
should attempt his trip without spare fuel?



Regards


Donal
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