Functionality level 1 
Functionality level 2 
Function 
Input information 
Output information 
3.1.3 Assess comparison 
• Result information from 3.1.2 
• Assessing whether correction (speed or rudder 
position) of manoeuvre is necessary and possi 
ble 
3.1.4 Provide result of 
comparison 
• Result information from 3.1.3 
• If necessary and possible: arrange correction of 
manoeuvre 
4. Return to the planned 
track 
4.1 Plan return 
4.1.1 Record input data 
• Present state variables of ship 
(position, course, speed) 
• Hydrographic and geographical 
information from the sea chart 
• Set track 
• Necessary input information is available 
4.1.2 Evaluate data 
• Result information from 4.1.1 
• Planned route for return to the original set track 
• Courses and speeds for the individual sections 
of the route 
4.1.3 Provide information 
• Result information from 4.1.2 
• Planned route (“way points", set courses and 
speeds for route sections) are available 
4.2 Execute return 
4.2.1 Record information 
• Deviation between planned 
route (set course and speed) 
and present values of ship 
• Distance of actual ship position 
from the planned route 
• Necessary input data for return to the set track 
4.2.2 Assess information 
• Result information from 4.2.1 
• Necessary actions (set values for course/rudder 
angle and speed) In order to return to the set 
track 
4.2.3 Act 
• Set course/rudder angle 
• Set speed/ 
speed regulator position 
• Necessary change in course/speed of ship for 
return to set track