Volvo Penta 21182210, Operator'S Manual

Page: 12 / 192

Underway Operation
Do not sit on, occupy or hang on any stern appendages
(e.g., swim platforms, boarding ladders, etc.) while
underway. Do not body surf, commonly known as “teak
surfing” or “platform dragging,” in the wake of the boat.
Do not tow persons in close proximity to the stern of
the boat.
Backdrafting (Station Wagon Effect)
Backdrafting is caused by air movement over or
around a boat creating a low pressure or suction area
around the stern that can increase CO level on the
boat. Backdrafting can be affected by relative wind
direction, boat speed, and boat trim angle. At certain
speeds and under certain operating conditions the low
pressure area may form in other regions and permit
carbon monoxide to enter the hull through openings
that are not at the back of the boat.
Other factors during boat operation which may affect
carbon monoxide concentration include:
● Adding or removing canvas may raise or lower
CO levels. Image #51618 illustrates desired air-
flow through the boat. As shown in image
#51619, certain canvas configurations, such as
side curtains and position of hatches, can
increase backdrafting.
● Intentional or unintentional excessive trim angle
(e.g., high bow angle or excessively unequal dis-
tribution of weight) may raise the CO level and
should be avoided (see image #51620).
51616
51617
51618
51619
51620
Safety Information
10 47700387 06-2009