Conditions Affecting Performance - Mercury GO BOLDLY 25 EFI Operation, Maintenance And Installation Manual

• When using your boat for waterskiing or similar activities, always keep a
fallen or down skier on the operator's side of the boat while returning to
attend to the skier. The operator should always have the down skier in
sight and never back up to the skier or anyone in the water.
Report accidents.
• Boat operators are required by law to file a boating accident report with
their state boating law enforcement agency when their boat is involved in
certain boating accidents. A boating accident must be reported if 1) there
is loss of life or probable loss of life, 2) there is personal injury requiring
medical treatment beyond first aid, 3) there is damage to boats or other
property where the damage value exceeds $500.00, or 4) there is
complete loss of the boat. Seek further assistance from local law
enforcement.

Conditions Affecting Performance

WEATHER
It is a known fact that weather conditions exert a profound effect on the power
output of internal combustion engines. Established horsepower ratings refer to
the power the engine will produce at its rated RPM under a specific
combination of weather conditions.
Corporations internationally have settled on adoption of International Standards
Organization (ISO) engine test standards, as set forth in ISO 3046,
standardizing the computation of horsepower from data obtained on the
dynamometer. All values are corrected to the power the engine will produce at
sea level, at 30% relative humidity, at 25 °C (77 °F) temperature, and a
barometric pressure of 29.61 inches of mercury (in. Hg).
Summer conditions of high temperature, low barometric pressure, and high
humidity all combine to reduce the engine power. This, in turn, is reflected in
decreased boat speeds as much as 3 to 5 km/h (2 to 3 mph) in some cases.
Nothing will regain this speed for the boater but cooler, dry weather.
Pointing out the consequences of weather effects, an engine running on a hot,
humid day may encounter a loss of as much as 14% of the horsepower it would
produce on a dry, brisk day. The horsepower that any internal combustion
engine produces, depends upon the density of the air that it consumes. The
density of air is dependent upon the ambient air temperature, the barometric
pressure, and the humidity (water vapor) content.
WEIGHT DISTRIBUTION (PASSENGERS AND GEAR) INSIDE THE
BOAT
Shifting weight to rear (stern):
• Generally increases speed and engine RPM
• Causes bow to bounce in choppy water
• Increases danger of following wave splashing into the boat when coming
off plane
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GENERAL INFORMATION
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