Boat designer Jim
Michalak spends a lot of time working out powerboat
performance in detailed measurements of speed vs. weight and
horsepower and other esoteric stuff. Geek that I am, I find
all this endlessly fascinating, but I never have the patience
do formal experiments to add my own findings to the data set.
Instead, I seem to work from informal experiments that just
seem to happen when I’m out goofing off in the boat. In
the interest of science, here’s the story of how I got
my latest data point.
was motoring down the lake on a Wednesday evening, in my AF4,
when I noticed a PWC with two riders towing another PWC and
rider. All were trying frantically to wave me down. (The lake
is a very lonely place on a Wednesday evening at sundown.) I
went over to them, and they told me their tale of misadventure
and woe. The PWCs were the property of one of the rider’s
boss. They had departed his dock, about 12 miles from their
current location after each putting $10 worth of gas in their
borrowed PWCs, heading for a destination they did not know was
nearly 20 miles from where they began. They also had no idea
that their boats only get about two to four miles per gallon.
Well, they never found their destination. So they
rode around checking out some of the hundred coves in the area
looking for it. Then one of the skis ran out of gas. Using an
old fish stringer as a painter they towed the dead one to a
marina nearby with the remaining ski, only to find that the
fuel dock was closed. Secure in the knowledge this was not the
only marina on the lake (because they had ridden past several
on the way there), they decided to leave that place of safety
and try to tow the dead jetski to the next marina “just
around the bend” or so they thought. Problem was, the
nearest alternate marina was about 3.5 miles in the opposite
the direction they headed. The marina they thought was “just
around the bend” was at least 5 miles from where they
If you think jetskis get appalling fuel economy
at speed, let me tell you they do even worse at sub-planing
speeds towing another boat. By now our crew noticed there was
a fuel gauge on the remaining jetski, and it was dangerously
low. They were now a mile and a half from the marina they just
departed, it was getting dark, and they were on the verge of
having two dead jetskis. That’s when they saw me.
When I got there, they told me their situation.
I don’t think they expected my response, which was mostly
laughter as I expressed my opinion on how dumb they were for
not paying attention to the gas gauge and worst of all, leaving
a safe harbor with a disabled vessel in hopes of finding more
fuel somewhere else. I guess it takes a few years and a number
of bad experiences to learn that you should never intentionally
make a bad situation worse. But they were all about 18 or 19
years old and therefore completely clueless. The only redeeming
feature of this empty-headed crew was that one of them was female,
good-looking, and in a tiny bathing suit.
They asked me if I could give them some of my
gas to get back home. My AF4
only has a 3 gallon gas tank which ordinarily is more fuel than
I can burn in a day of boating. She’ll run 50 miles or
more on 3 gallons, depending on how fast I want to go. But it’s
still not that much gas. Again, they were surprised at my laughter.
I explained I only had about two and a half gallons on board
to split between them. Figuring in the best case their boats
could go 4-5 miles on a gallon, and they had to go something
like 13 miles to get home, giving them even all of my gas would
do them no good at all. (All the fuel docks on the lake are
closed by now.) Not to mention that it would put me in unnecessary
I wasn’t going to tow them the13 miles back
to their home dock. Instead, I offered to tow the dead jetski
to a nearby Army Corps boat ramp where they could get on the
phone and find out who their real friends were! We rigged a
line, and I took the dead PWC in tow. As soon as we started
moving, their other boat ran out of gas too.
So where’s the science, you ask? Okay, here
comes the performance data point: I now had two PWCs in tow,
about 1200 lbs total. I also had three teenage passengers aboard
in the form of two skinny boys and a lovely, scantily clad young
lady. Including myself and my gear, I figure a total payload
of around 700 lbs. My boat and motor weigh around 500-550 lbs.
All told we had 1250 lbs in the boat and were towing about that
much. With just me aboard, my boat will run 22 mph wide open.
In this configuration, we saw only 6 mph maximum, no matter
what throttle setting. The motor wouldn’t rev either.
My 9” pitch prop was just too tall for this load.
(While I did have my digital camera with me, I’m
afraid that I neglected to take any photos of this scene, particularly
of the more attractive member of my new crew. Hopefully the
lack of pictorial documentation won’t render this important
data point moot in the eyes of my peers in the small powerboat
scientific community.) Editor's
note: we have included a picture of John with his daughter as
well as a couple of shots of his AF4 to make the article more
On the way back we laughed a bit about their
predicament. I observed how fortunate they were to have a woman
along, as that would give them the opportunity to extend their
suffering many, many days beyond this evening. Judging from
the downcast faces, they had already realized this. She shot
me a look that said “You don’t know the half of
The 19th century author Ambrose Bierce once defined
happiness as “the agreeable sensation arising from contemplating
the misery of others.” At this moment, I truly understood
what he meant.
We eventually got hold of the PWCs’ owner
on my cell phone and arranged to have him come and deal with
his foolish employee and friends. When I left them, they still
had lots of problems to deal with. How to get the two dead jetskis
back to their dock, after dark and without a trailer? How to
appease the P-O’ed girlfriend, and what exactly to say
to the boss? At least they were safe, and maybe, just maybe,
they learned something. And I got my data point! Ain’t