|

DORADO, POWER CUDDY SKIFF, 18' X 5.5',
650 POUNDS EMPTY
Dorado is a Southern Hemisphere constellation
and also this boat designed for Ashley Cook in New South
Wales. The idea behind it was for a rough water power
boat with a sleepable cuddy cabin. We started with my
Frolic2 sailboat (which itself evolved from the Toto canoe)
and straightened out the stern lines to adapt it for planing
power. After mocking it up Ashley said he and family needed
another 3" of headroom so Dorado B was born and built.
The plans show it both ways. I should add that even though
Dorado started out as a modified sailing hull, it probably
would be a terrible sailer just as Frolic2 would be a
terrible power boat on plane. The two worlds just don't
mix and the idea of "just hoisting a simple sail"
on Dorado is bound to be a sure loser both because it
will sail poorly and because you will lose the simplicity
of a straight power boat. Not that the idea isn't worth
more study. It would take a special person to do all the
tweaking involved with making the two-way boat work well.

The shape works! Ashley has been running
DoradoB into the rough stuff. In the above photo he is
off the east coast of Australia with nothing but ocean
between him and New Zealand. He says the big curling wave
to his side is a permanent fixture and fatal to boaters
trying it. He is using a new 30 hp two stroke motor which
still is in its break in period. The Coast Guard would
say that is the max for this hull. With the 30 Ashley
reports cruising at about 20 mph with two adults on board.
As an aside I should mention that in boats like this one
needs to pay attention to the prop specs to prevent the
motor from going over redline at full throttle. If the
usual prop is for a heavier and slower boat then I would
expect the motor to rev too high at full throttle in a
lighter faster boat. The idea is to select a prop with
a pitch that will put the tach on the red line at full
throttle.

The hull is made with taped seams
needing two sheets of 1/2" plywood and eight sheets
of 3/8" plywood, a total of about 400 pounds of wood.
I would expect the stripped hull to weigh about 500 pounds
with framing and fiberglass. I would add at least 150
pounds to that for a motor and its gear which is why I
estimate the empty weight to be about 650 pounds. Add
two adults and fuel and now you are around 1100 pounds
total. The old rule for motors on planing powerboats is
a horse for each 50 pounds so if you havea 25 horse motor
you will be able to cruise this boat at 2/3 throttle.
I would say 15 hp is the minimum you might use and expect
to plane, even then you must stay very light and run near
full throttle.
 |