Outgoing NMEA messages follows:
VMVLW / VDVLW $VMVLW,.…,Trip and total
VMMTW / VDMTW $VMMTW,…,Water temperature
VMVHW / VDVHW $VMVHW,…,Relative speed through water
VMVBW / VDVBW $VMVBW,....,Multiple speed
VMXDR / VDXDR $VMXDR,....,Speed direction
VMALR / VDALR $VMALR,....,Cause