Appendix; Advice On Operation - Simrad TP20 Manual

6 Appendix

6.1 Advice On Operation

The Simrad Tillerpilot when used correctly can maintain as good a course, on most points of sail as
a skilled helmsman, with the advantage that they never lose concentration where a human may
begin to show lapses of concentration after as little as ten minutes.
There are certain circumstances however, where a human pilot has the advantage in being able to
anticipate events which no autopilot can sense, typically in a heavy following sea. The
following advice should improve efficiency when sailing using Tillerpilot:
1. When sailing close to the wind, it is easy to forget to trim the mainsail, allowing excessive weath-
er helm to build up. Where a human helmsman would quickly complain, the autopilot will strug-
gle on, and the boat will be sailed less efficiently. Whereas a human normally likes to feel some
weather helm, this is not necessary for the functioning of the Tillerpilot. Power consumption, wear
and drag will be greatly reduced if the mainsail is freed or reefed a little sooner than normal when
sailing manually.
2. It is also advisable when sailing close hauled to set a course a few degrees free of that normally
sailed under manual control, to avoid luffing into the wind.
3. When running dead downwind, a human pilot can see visual signs warning him if the boat is
about to gybe, which the Tillerpilot cannot sense. Therefore, when under autopilot it is advisable
not to sail as close to the gybe as you may do when sailing manually.
4. When broad reaching or running fast, particularly with quartering waves, a helmsman will nat-
urally apply periodic larger angles of helm than when beating or sailing slowly. This is the equiv-
alent of increasing rudder Gain, and it may be a good idea to adjust the Gain on the Tillerpilot.
Many people prefer to find a compromise setting which is used for all sailing, but with practice it
can be optimised for different conditions e.g. low for motoring in a calm sea or high for running
fast. If the Gain is set too low, the boat will yaw because insufficient rudder is applied in time; if
the gain is too high, the boat will continually overcorrect on each deviation, increasing power con-
sumption.
5. The Tillerpilot is a highly advanced piece of equipment - as such, it is a valuable aid to enjoy-
able sailing. However, it would be a mistake to become complacent. As with all electronic navi-
gational equipment, it is an aid to navigation and should not be used as a substitute for conven-
tional navigational practice. Remember - Maritime Law* requires that you keep a good look out
at all times.
*IMO International Regulations for Preventing Collisions at Sea, Part B Rule 5 (1972)
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