Volvo Penta D4 Operator's Manual page 27

Instruments and Controls
high waves, the bow will plough downwards into the
water. The boat can start to steer with the bows or yaw
suddenly so that passengers may be thrown over-
board.
The boat's trim shall always be adjusted to give well
balanced steering. Certain combinations of boat,
engine and propeller can cause instability and/or self-
steering tendencies when the boat is driven at or close
to the maximum "bow up" or "bow down" positions. The
stability and steering characteristics of the boat can
also vary depending on the sea conditions. Contact
your Volvo Penta dealer to correct these tendencies if
your boat shows instability an/or self-steering tenden-
cies.
At planing speed
Trim the drive to the angle that gives the most stable
and comfortable feeling. If the boat has a twin instal-
lation, the drive can be trimmed to different angles to
compensate for side winds and, to a certain degree,
uneven load distribution.
Driving with "bow down"
The "bow up" position is normally used for driving at
cruising speed, in short seas, or at full speed. With
full "bow up" the boat can have a tendency to self-steer.
You may have to compensate with the rudder to keep
the boat on the right course. In this position, the bow
of the boat tries to lift out of the water. Excessive "bow
up" trim causes propeller cavitation, so that the pro-
peller looses its grip. The engine speed increases with-
out the boat speed increasing, in fact the boat might
even sink.
Be careful when driving in short seas. Excessive "bow
up" trim may cause the boat to bounce quickly
upwards, with the risk of throwing passengers over-
board.
In short seas or heavy head seas
Trim the drive down so that the bow drops. This makes
for a more comfortable journey. Refer to section Driv-
ing with "bow down".
Driving in Beach range
The beach range is used for driving at reduced speed
in shallow water or where the depth is unknown.
The highest permitted engine speed when in the Beach
range is 1500 rpm.
IMPORTANT!
Make sure the drive's coolant inlet is never trimmed out
of the water when operating in the beach range..
7748934 04-2008 25