Volvo Penta IPS Operator's Manual page 7

Carbon monoxide poisoning
When a boat moves forwards, an area of low pressure
air forms behind the boat. In adverse conditions, this
low pressure can be so strong that the boat's own
exhaust fumes are sucked into the cockpit or cabin,
which entails a risk of carbon monoxide poisoning for
all aboard.
The problem of low-pressure suction is worst in high,
wide boats with a square transom. But even in other
types of boats, low-pressure suction can be a problem
in some conditions, such as if you drive with the hood
up. Other factors which increase the low-pressure
effect are wind conditions, load distribution, pitching,
trimming, open windows and ventilators etc.
Remember
• Safety equipment: Life jackets for everybody aboard, communication equipment, emergency
rockets, approved fire extinguisher, first aid kit, life buoy, anchor, paddle, torches etc.
• Spare parts and tools: Impeller, fuel filters, fuses, tape, hose clamps, engine oil, propeller and
tools for the jobs you could be expected to have to do.
• Take your chart out and study your planned route. Calculate distance and fuel consumption.
Listen to weather reports.
• Tell your friends/relatives about route plans if you undertake a long journey. Remember to
notify changed plans or delays.
• Inform everybody aboard about where the safety equipment is located, and how it works. Make
sure that there is more than one person aboard who can start and operate the boat safely.
This list can be extended, since the need for safety equipment varies with the type of boat, and
where or how it is used etc. We recommend that you ask a regional boat or sea safety organization
for more detailed maritime safety information.
7748921 04-2008
P0003073
Most modern boats are designed so that the problem
of low-pressure suction is very rare, however. If low-
pressure suction does occur anyway, do not open
hatches or ventilators in the forward part of the boat.
Strangely enough, this makes the problem worse. Try
changing speed, trimming or load distribution instead.
Also try taking down/opening the hood or modifying it
in some other manner. Ask your boat dealer for advice
about the best solution for your particular boat.
Safety Information
5