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5 Task area “Dealing with unplanned incidents”
This task area is used for considering incidents which are not foreseeable during the planning and ne
cessitate a divergence from the original voyage planning. The list of incidents considered here makes
no claim to completeness, but it should be assumed that the incidents dealt with here cover the over
whelming majority of the cases occurring in practical operation.
Within the framework of this analysis, the following unplanned incidents are considered:
• Collision avoidance: reaction to the particular traffic situation on the basis of the result
of the task: “Object recording” (Section 4.3).
• Grounding avoidance: execution of a change in planning on the basis of the water
depth actually present. This task is based on the data recorded in the course of the
task “Observing the environment” (Section 4.2).
• Evasion of bad weather regions: change in planning with the aim of evading bad
weather regions. This task likewise uses the data recorded in the course of observing
the environment.
• Execution of man-overboard manoeuvres.
One factor common to the tasks itemised here is that they represent a combination of planning activities
(i.e. recording and evaluating data) and “active” activities (i.e. execution of the particular manoeuvre to
deal with the situation). For this reason, each of these tasks comprises two general functionalities:
• Planning of the respective manoeuvre
• Execution of the manoeuvre; this includes return to the track originally planned.
5.1 Collision avoidance
5.1.1 Purpose of task
The process of collision avoidance consists of the planning and following of an evasion track with the
aim of avoiding collisions with other vessels. Thus collision avoidance - as already mentioned in the
introduction - consists of a planning component and an executing/monitoring component.
During the planning, the necessary data for determining the evasion manoeuvre and track are compiled.
A distinction should be made here between the terms “evasion track" and “evasion manoeuvre”. The
evasion manoeuvre designates the actions which are initiated to avoid the risk of collision. This ma
noeuvre is undertaken on the basis of the encounter situation and must follow the international rules for
the avoidance of collisions, as well as those of “good seamanship”. The selected manoeuvre forms the
planning basis for the evasion track. In the case of evasion by changing course, a sequence of way
points is involved, which leads from leaving the set track via passing the foreign vessel through to re
newed joining of the set track.
The execution and monitoring of the evasion track contains similar components such as the tasks “De
termining set/actual deviations” (Section 3.1) and “Determining set value” (Section 3.2). Essentially, the