Functionality level 1 
Functionality level 2 
Function 
Input information 
Output information 
1.5 Determine longit. 
speed through water 
1.5.1 Provide data and 
criteria 
• See Table 4 
• Different STWX 
1.5.2 Compare data and 
criteria 
• Result information from 1.5.1 
• Accuracy of all input variables 
• Plausibility criteria 
• Statement concerning the consistency and plausi 
bility of the measured values 
1.5.3 Assess result of 
comparison 
• Result information from 1.5.2 
• Consistency criteria 
• Is a measured value usable? 
1.5.4 Selection of data to 
be provided 
• Result information from 1.5.1 
• Result information from 1.5.3 
. STWX 
1.5.5 Provision of data 
• Result information from 1.5.4 
• Representation of the selected measured value for 
the navigator 
• Display if measured values inconsistent 
• Provision of measured values for further processing 
1.6 Determine transv. 
speed through water 
1.6.1 Provide data and 
criteria 
• See Table 4 
• Different STWY, 
1.6.2 Compare data and 
criteria 
• Result information from 1.6.1 
• Accuracy of all input variables 
• Plausibility criteria 
• Statement concerning the consistency and plausi 
bility of the measured values 
1.6.3 Assess result of 
comparison 
• Result information from 1.6.2 
• Consistency criteria 
• Is a measured value usable? 
1.6.4 Selection of data to 
be provided 
• Result information from 1.6.1 
• Result information from 1.6.3 
. STWYx 
1.6.5 Provision of data 
• Result information from 1.6.4 
• Representation of the selected measured value for 
the navigator 
• Display if measured values inconsistent 
• Provision of measured values for further processing 
1.7 Determine water 
depth under keel 
1.7.1 Provide data and 
criteria 
• See Table 4 
. Different DEPTH*