Functionality level 1 
Functionality level 2 
Function 
Input information 
Output information 
4.3 Monitor return 
4.3.1 Record set and ac 
tual value 
• Planned route for return to the 
set track, set values for courses 
or speeds 
• State variables of ship: position, 
course, speed 
• Necessary input information to determine 
set/actual deviation is recorded 
4.3.2 Compare set and 
actual value 
• Result information from 4.3.1 
• Distance of ship from planned route 
• Set/actual difference for course 
• Set/actual difference for speed 
4.3.3 Assess comparison 
• Result information from 4.3.2 
• Decision whether planned route to return to the 
original set track can be reached 
4.3.4 Provide result of 
comparison 
• Result information from 4.3.1 
• Result information from 4.3.2 
• Set/actual deviations are available for further 
use