NMEA VBW datagram format
The NMEA VBW datagram contains water- and ground-referenced vessel speed data.
Format
$--VBW,x.x,z.z,A,r.r,q.q,A,p.p,A,c.c,A*hh<CR><LF>
Description
1 $—Talker identifier
2 VBWDatagram identifier
3 x.xSpeed relative to waterLongitudinal (knots)
4 z.zSpeed relative to waterTransverse (knots)
5 ASpeed relative to waterStatus
•  A = The data are valid.
•  V = The data are not valid.
6 r.rSpeed relative to groundLongitudinal (knots)
7 q.qSpeed relative to groundTransverse (knots)
8 ASpeed relative to groundStatus
•  A = The data are valid.
•  V = The data are not valid.
9 p.pSpeed relative to waterSternTransverse (knots)
10 ASpeed relative to waterSternStatus
•  A = The data are valid.
•  V = The data are not valid.
11 c.cSpeed relative to groundSternTransverse (knots)
12 ASpeed relative to groundSternStatus
•  A = The data are valid.
•  V = The data are not valid.
13 *hhChecksum