Proper Motor Height
The key to going fast on the water begins with having
the outboard height set correctly. Once a laborious
process, changing outboard height on most bass boats is
now as easy as turning a dial to raise or lower a hydraulic
jack plate, which is now standard on most rigs.
If you don’t have a hydraulic plate, invest in one if pos-
sible. Proper engine height can still be obtained with a
manual plate, but it greatly increases the time and effort
required to achieve the best setting.
Regarding engine height, many bass boat owners believe
the key to speed is to adjust trim, but they’re off the mark.
“To go fast, you want the nose of the boat as low as pos-
sible,” says Alan Stinson.
A hydraulic jack plate is a valuable tool for maximizing speed.
[including fuel, anglers, batteries, etc.], so we perform
tests with that load,” says Mark Hanson, Mercury Marine’s
lead hydrodynamic technician.
Hanson says boats react negatively to heavy loads, so
weight must be continuously considered. In fact, Hanson
often refuels several times throughout the testing cycle to
ensure the heavy weight of full fuel tanks is taken into con-
sideration. A different prop is often required to lift a boat
that’s full of gear, and pitch size must be adjusted.
With the correct prop and weighting determined,
run speed trials at different motor heights. Hanson
begins by performing an anti-ventilation plate (AVP;
commonly referred to as the cavitation plate) measure-
ment. This determines the height of the AVP above the
centerline of the hull. Boat owners can do
it themselves by running a straight edge
from the center bottom of the hull to the
motor. With the motor trimmed down,
the AVP should start about 6 inches above
that line. Adjust the jack plate to achieve
that mark.
From that starting point, run tests on the
water to determine the best trim angle and
whether or not the motor should be raised
or lowered with the jack plate. The objective
is to get most of the boat out of the water
without the excessive use of trim while
maintaining a smooth, stable ride. Through
experimentation, you should be able to dial
in what works best for your rig.
Tackle Load
As mentioned, weight is a major factor in
achieving speed.
“Loading the front of the boat is enemy No. 1,” says
Stinson.
Stinson, who was known to weigh each pro team mem-
ber boat when it came into the factory, recalls once moving
273 pounds of tungsten weights and plastics out of the
front of a well-known pro’s boat.
“Put all the heavy gear in the back,” he insists.
Stinson is credited with designing and building many of
the first modern bass boats in the 1970s for Skeeter. With
more than 40 years of experience, he is responsible for
many cutting-edge hull designs, and for helping evolve
bass boats into what they are today. Any discussion of the
evolution of speed in bass boats circles back to him.
Stinson says that keeping the nose low creates less
wind drag and actually places less of
the boat in the water. In contrast, trim-
ming up lifts the nose, pushing more of
the rear of the boat down and creating
more hydrodynamic (water) drag.
“That causes a wake,” Stinson adds,
“and a wake is a telltale sign of drag.”
Before setting engine height, consider
two variables: First, be sure your boat has
the recommended prop for its outboard.
Each prop has an RPM range in which it
performs best, and if your outboard isn’t
capable of turning the prop within that
range, consult your outboard manufac-
turer’s list (readily available through your
dealer) of prop recommendations for the
motor. Second, be sure to run tests in
real-world conditions. If it’s tournament
top-end you’re trying to improve, load
the boat for a tournament.
“A tournament fisherman carries
Even a small tackle load can add up to a lot of weight, which can rob from top-end speed.
about 1,500 pounds of gear in the boat
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