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2. Observing meteorological data: 
2.1 Observing wind direction and speed 
3. Observing drift. 
4.2.3 Functions 
The functionalities of task “Observing the current environmental situation” are of the “Data recording” 
type. They are thus composed from the elementary individual functions “Record input data”, “Evaluate 
data” and “Provide information”. 
Annex 7.4.2 contains the functionalities identified for this task as well as the elementary individual func 
tions with their input and output data, in overview form. 
4.3 Object recording 
The task “Object recording” serves to record information concerning objects which are not registered on 
sea charts. Unlike environmental observation (Section 4.2), which serves the purposes of observation 
of “natural environmental parameters”, this task considers “artificial objects". A distinction must be 
made here as to the way in which the movement data of the observed objects are determined: 
• In “conventional” observation methods (visual observation, radar/ARPA), the move 
ment data of objects are initially determined in relation to the own ship. From these 
can be calculated the absolute movement of the object, bearing in mind the movement 
of the own ship. 
• On receiving absolute object data, e.g. via transponders (AIS), absolute movement 
data of foreign objects are directly available. 
4.3.1 Purpose of task 
The purpose of the task “Observing the current traffic situation” is the recording of all data of the objects 
itemised above, insofar as these are relevant to the own ship. These include: 
• Type and position of the identified fixed objects 
• Type, position and movement of the observed movable objects. The data to be re 
corded are obtained primarily on the basis of their usage for fulfilling the task of colli 
sion avoidance (see Section 5.1). Taken individually, the following items of information 
concerning foreign vessels must be available: 
• Type of vessel according to regulations on collision avoidance 
• Bearing and position of vessel calculated on the own ship 
• Courses and speeds (relative/true) 
• Range of vessel 
• Derived characteristic variables for assessing the encounter situation: CPA, 
TCPA