Riva 90 ARGO - Yacht Operation During Navigation

12 - INFORMATION FOR USE353
12.10 YACHT OPERATION DURING NAVIGATION
WARNING
Persons operating your yacht must never be under the inuence of al-
cohol or drugs. The yacht’s pilot should be experienced in the use of all
instruments and controls, and know the handling characteristics of the
yacht at all speeds and sea conditions.
You should be certain that persons intending to operate your yacht are
completely knowledgeable about its proper operation. If you are not cer-
tain about an individual’s qualications or competence, the person must
be supervised by a qualied operator.
The yacht is manoeuvred by means of the steering wheel in the helm sta-
tion. The steering wheel operates the rudders by means of an electro--hy-
draulic system. The steering gear operation is independent from the engine
operation. Never leave the steering wheel unattended when the yacht is
navigating.
Keep in mind that the rudder effect is proportional to the propeller rpm and
the yacht’s speed, especially when moving forward.
As a consequence, the rudder efciency is high at high rpm and speed.
On the contrary, when the engines are idling and the yacht’s speed is low,
the yacht’s reaction to the tiller angle is almost negligible.
If necessary, or when in restricted waters, you can steer the yacht with the
engines by varying and/or reversing the engine speeds and alternating pow-
er from port and starboard engine.
At low rpm, operating on a single engine, alternating port and starboard en-
gines and using the “back and ll” method for turning the yacht is the recom-
mended practice. Learn and practice the skills for handling the yacht at low
speed and engine rpm.
When the yacht’s speed increases, the transition of the hull from displace-
ment mode to planing mode is a critical phase.
The transition to the planing mode should be done as quickly as practical to
achieve fuel efciency and provide a comfortable motion.
The minimum planing speed depends on yacht’s displacement, on load dis-
tribution, on interceptors position and on sea conditions.
Adjust speed and interceptors position according to sea conditions and to
the loading conditions of the yacht, in order to ensure an easy yacht move-
ment and to avoid stress to the structure due to the effects of sea conditions.
WARNING
At high speed, the use of the autopilot is dangerous and not recommend-
ed. Anyway, be always very careful during navigation also when the au-
topilot is in use.
The high quality engines allow the yacht to be run safely at cruising speed
for extended periods of time.