Message ID 
6 
Identifier for Message 8 
Repeat Indicator 
2 
Used by the repeater to indicate how many times a message has been repeated. 0=default; 3= do not repeat any more 
Source ID 
30 
MMSI number of source station 
Spare 
2 
Not used. Should be zero 
DAC 
10 
International DAC. (DAC=100=1100100b) should be 224 or 225 
FI 
6 
Function identifier. (FI=100=1100100b) heading says 50 
Hour Generation 
5 

Minute Generation 
6 

Second Generation 
6 

Geometry Aft 
2 
Geometry form of the aft section. See Table Geometry. 
Geometry Bow 
2 
Geometry form of the bow section. See Table Geometry 
Geometry Curve 
2 
Geometry during direction change. See Table Geometry. 
Geometry 3D Above WL 
2 
Geometry form 3D above water level. 
Geometry 3D Under WL 
2 
Geometry form 3D under water level. 
Longitude Point 1 
28 
Longitude in 1/10000min. If rectangle is the geometry used for Aft: Point 1= Point Aft[3]. If the envelope using ELLIPSE as whole envelope Point 1=Point Aft[269].

Latitude Point 1 
27 
Latitude in 1/10000min 
Longitude Point 2* 
28 
Longitude in 1/10000min. Point 2= Point Aft[2] 
Latitude Point 2* 
27 
Latitude in 1/10000min 
Longitude Point 3 
28 
Longitude in 1/10000min. If rectangle is the geometry used for Aft: Point 3= Point Aft[0] = Point Curve[0]. If the envelope using ELLIPSE as whole envelope Point 3=Point Aft [0] 
Latitude Point 3 
27 
Latitude in 1/10000min 
Longitude Point 4* 
28 
Longitude in 1/10000min. Point 4= Point Aft[4] 
Latitude Point 4* 
27 
Latitude in 1/10000min 
Longitude Point 5 
28 
Longitude in 1/10000min. If rectangle is the geometry used for Aft: Point 5= Point Aft[1] = Point Curve[1]. If the envelope using ELLIPSE as whole envelope Point 5=Point Aft [179] 
Latitude Point 5 
27 
Latitude in 1/10000min 
Longitude Point 6 
28 
Longitude in 1/10000min. Point 6= Point Curve[2] = Point Bow[2] 
Latitude Point 6 
27 
Latitude in 1/10000min 
Longitude Point 7 
28 
Longitude in 1/10000min. Point 7= Point Curve[4] 
Latitude Point 7 
27 
Latitude in 1/10000min 
Longitude Point 8 
28 
Longitude in 1/10000min. Point 8= Point Curve[3] = Point Bow [1] 
Latitude Point 8 
27 
Latitude in 1/10000min 
Longitude Point 9 
28 
Longitude in 1/10000min. If triangle is the geometry used for bow: Point 9=Point Bow [0]. If Ellipse is the geometry used for bow: Point 9=Point Bow [89]. 
Latitude Point 9 
27 
Latitude in 1/10000min 
Longitude Point 10 
28 
Longitude in 1/10000min. If rectangle is the geometry used for 3DaboveWL and 3DunderWL: Point 10=Point 3DaboveWL[0] = Point 3DunderWL[0]. If Ellipse is the geometry used for 3DaboveWL and 3DunderWL: Point 10=Point 3DaboveWL[0] = Point 3DunderWL[179]. 
Latitude Point 10 
27 
Latitude in 1/10000min 
Altitude Point 10 
17 
Altitude (+/)40m * 1000. Resolution: 0.001. 
Longitude Point 11 
28 
Longitude in 1/10000min. If rectangle is the geometry used for 3DaboveWL: Point 11= Point 3DaboveWL[1]. If Ellipse is the geometry used for 3DaboveWL: Point 11= Point 3DaboveWL[89]. 
Latitude Point 11 
27 
Latitude in 1/10000min 
Altitude Point 11 
17 
Altitude (+/)40m * 1000. Resolution: 0.001. 
Longitude Point 12** 
28 
Longitude in 1/10000min. Point 12= Point 3DaboveWL[2]. 
Latitude Point 12** 
27 
Latitude in 1/10000min 
Altitude Point 12** 
17 
Altitude (+/)40m * 1000. Resolution: 0.001. 
Longitude Point 13 
28 
Longitude in 1/10000min. If rectangle is the geometry used for 3DaboveWL and 3DunderWL: Point 13=Point 3DaboveWL[3] = Point 3DunderWL[1]. If Ellipse is the geometry used for 3DaboveWL and 3DunderWL: Point 13=Point 3DaboveWL[179] = Point 3DunderWL[0]. 
Latitude Point 13 
27 
Latitude in 1/10000min 
Altitude Point 13 
17 
Altitude (+/)40m * 1000. Resolution: 0.001. 
Longitude Point 14 
28 
Longitude in 1/10000min. If triangle is the geometry used for 3DunderWL: Point 14=Point 3DunderWL[2]. If Ellipse is the geometry used for 3D under WL: Point 13=Point 3DunderWL[89]. 
Latitude Point 14 
27 
Latitude in 1/10000min 
Altitude Point 14 
17 
Altitude (+/)40m * 1000. Resolution: 0.001. 
Total Bits 
949 
Occupies 5 slots 