Propeller Effect; Maneuvering Techniques - Formula Fastech Service Manual

FASTECH

PROPELLER EFFECT

The effects of unequal propeller thrust, wind and
current must also be kept in mind. While wind and
current may not always be present, an
experienced boater will use them to his
advantage.
Propeller Effect
Figure 7-3
Twin-engine craft with counter-rotating drive units
operate with less propeller-torque-induced drifting
as compared to the same craft with like-rotating
drives or, for that matter, single-engine boats with
one propeller. This helps maintain an even keel,
as the torque of the counter-rotating propellers is
effectively a "wash."
MANEUVERING
TECHNIQUES
Steering response depends on drive unit position,
trim tab position, motion and throttle.
7-6
1
KC-2340
1. Stern Circle
2. Bow Circle
Wandering is a characteristic of all deep vee hulls
at slow speed. There is no cure for wandering,
however, a very basic operational technique can
be applied which will minimize this characteristic.
If the steering wheel is moved back and forth to
compensate for wandering, invariably, the
situation will be magnified. If the steering wheel
remains in a centered position, the boat will
wander back and forth slightly, however, the
overall course of the boat will be a straight one.
When operating your Formula boat at low speeds,
use propeller thrust to maneuver the boat, do not
just turn the drive units. This enables you to
maneuver in a smaller area and have more
control of the boat. This technique is a
combination of propeller direction, engine thrust
and steering wheel maneuvers.
FASTECH
2
FOR173
Maneuvering
Figure 7-4
FORMULA