A talker typically sends a group of sentences at intervals determined by the unit's update rate, but generally not more often than once per second.

Characters following the “*” are a checksum. Checksums are optional for most sentences, according to the standard.

Autopilot format B

      APB,A,A,0.10,R,N,V,V,011,M,DEST,011,M,011,M
         A            Loran-C blink/SNR warning
         A            Loran-C cycle warning
         0.10         cross-track error distance
         R            steer Right to correct (or L for Left)
         N            cross-track error units - nautical miles
         V            arrival alarm - circle
         V            arrival alarm - perpendicular
         011,M        magnetic bearing, origin to destination
         DEST         destination waypoint ID
         011,M        magnetic bearing, present position to destination
         011,M        magnetic heading to steer
                      (bearings could be given in True as 033,T)
         (note: some pilots, Roberston in particular, misinterpret "bearing
         from origin to destination" as "bearing from present position to
         destination".  This apparently results in poor performance if the
         boat is sufficiently off-course that the two bearings are
         different.)

Bearing - origin to destination waypoint

      BOD,045.,T,023.,M,DEST,START
         045.,T       bearing 045 True from "START" to "DEST"
         023.,M       breaing 023 Magnetic from "START" to "DEST"
         DEST         destination waypoint ID
         START        origin waypoint ID

Bearing and distance to waypoint - great circle

      BWC,225444,4917.24,N,12309.57,W,051.9,T,031.6,M,001.3,N,004*29
         225444       UTC time of fix 22:54:44
         4917.24,N    Latitude of waypoint
         12309.57,W   Longitude of waypoint
         051.9,T      Bearing to waypoint, degrees true
         031.6,M      Bearing to waypoint, degrees magnetic
         001.3,N      Distance to waypoint, Nautical miles
         004          Waypoint ID

Bearing and distance to waypoint - rhumb line

              (format same as BWC)

Depth below transducer

      DBT,0017.6,f,0005.4,M
         0017.6,f     17.6 feet
         0005.4,M     5.4 Metres

Global Positioning System Fix Data

      GGA,123519,4807.038,N,01131.324,E,1,08,0.9,545.4,M,46.9,M, , *42
         123519       Fix taken at 12:35:19 UTC
         4807.038,N   Latitude 48 deg 07.038' N
         01131.324,E  Longitude 11 deg 31.324' E
         1            Fix quality: 0 = invalid
                                   1 = GPS fix
                                   2 = DGPS fix
         08           Number of satellites being tracked
         0.9          Horizontal dilution of position
         545.4,M      Altitude, Metres, above mean sea level
         46.9,M       Height of geoid (mean sea level) above WGS84
                      ellipsoid
         (empty field) time in seconds since last DGPS update
         (empty field) DGPS station ID number

Geographic position, Latitude and Longitude

      GLL,4916.45,N,12311.12,W,225444,A
         4916.46,N    Latitude 49 deg. 16.45 min. North
         12311.12,W   Longitude 123 deg. 11.12 min. West
         225444       Fix taken at 22:54:44 UTC
         A            Data valid
           (Garmin 65 does not include time and status)

GPS DOP and active satellites

      GSA,A,3,04,05,,09,12,,,24,,,,,2.5,1.3,2.1*39
         A            Auto selection of 2D or 3D fix (M = manual)
         3            3D fix
         04,05...     PRNs of satellites used for fix (space for 12)
         2.5          PDOP (dilution of precision)
         1.3          Horizontal dilution of precision (HDOP)
         2.1          Vertical dilution of precision (VDOP)
           DOP is an indication of the effect of satellite geometry on
           the accuracy of the fix.

Satellites in view

      GSV,2,1,08,01,40,083,46,02,17,308,41,12,07,344,39,14,22,228,45*75
         2            Number of sentences for full data
         1            sentence 1 of 2
         08           Number of satellites in view
         01           Satellite PRN number
         40           Elevation, degrees
         083          Azimuth, degrees
         46           Signal strength - higher is better
         <repeat for up to 4 satellites per sentence>
              There my be up to three GSV sentences in a data packet

Heading, Magnetic

      HDM,235.,M
         HDM          Heading, Magnetic
         235.,M       Heading 235 deg. Magnetic
          (HDG, which includes deviation and variation, is recommended
          instead)

Command heading to steer

      HSC,258.,T,236.,M
         258.,T       258 deg. True
         236.,M       136 deg. Magnetic

Water temperature, Celcius

      MTW,11.,C
         11.,C        11 deg. C

List of waypoint IDs in currently active route

      R00,MINST,CHATN,CHAT1,CHATW,CHATM,CHATE,003,004,005,006,007,,,*05
         (This sentence is produced by a Garmin 65, but is not listed
         in Version 2.0 of the standard.  The standard lists RTE for
         this purpose.)

Recommended minimum navigation information (sent by nav. receiver when a destination waypoint is active)

      RMB,A,0.66,L,003,004,4917.24,N,12309.57,W,001.3,052.5,000.5,V*0B
         A            Data status A = OK, V = warning
         0.66,L       Cross-track error (nautical miles, 9.9 max.),
                              steer Left to correct (or R = right)
         003          Origin waypoint ID
         004          Destination waypoint ID
         4917.24,N    Destination waypoint latitude 49 deg. 17.24 min. N
         12309.57,W   Destination waypoint longitude 123 deg. 09.57 min. W
         001.3        Range to destination, nautical miles
         052.5        True bearing to destination
         000.5        Velocity towards destination, knots
         V            Arrival alarm  A = arrived, V = not arrived
         *0B          mandatory checksum

Recommended minimum specific GPS/Transit data

      RMC,225446,A,4916.45,N,12311.12,W,000.5,054.7,191194,020.3,E*68
         225446       Time of fix 22:54:46 UTC
         A            Navigation receiver warning A = OK, V = warning
         4916.45,N    Latitude 49 deg. 16.45 min North
         12311.12,W   Longitude 123 deg. 11.12 min West
         000.5        Speed over ground, Knots
         054.7        Course Made Good, True
         191194       Date of fix  19 November 1994
         020.3,E      Magnetic variation 20.3 deg East
         *68          mandatory checksum

Waypoints in active route

      RTE,2,1,c,0,W3IWI,DRIVWY,32CEDR,32-29,32BKLD,32-I95,32-US1,BW-32,BW-198*69
         2            two sentences for full data
         1            this is sentence 1 of 2
         c            c = complete list of waypoints in this route
                      w = first listed waypoint is start of current leg
         0            Route identifier
         W3IWI...     Waypoint identifiers

Water speed and heading

      VHW,259.,T,237.,M,05.00,N,09.26,K
         259.,T       Heading 259 deg. True
         237.,M       Heading 237 deg. Magnetic
         05.00,N      Speed 5 knots through the water
         09.26,K      Speed 9.26 KPH

Relative wind direction and speed

      VWR,148.,L,02.4,N,01.2,M,04.4,K
         148.,L       Wind from 148 deg Left of bow
         02.4,N       Speed 2.4 Knots
         01.2,M       1.2 Metres/Sec
         04.4,K       Speed 4.4 Kilometers/Hr

Track made good and ground speed

      VTG,054.7,T,034.4,M,005.5,N,010.2,K
         054.7,T      True track made good
         034.4,M      Magnetic track made good
         005.5,N      Ground speed, knots
         010.2,K      Ground speed, Kilometers per hour

Waypoint Closure Velocity

Distance to Waypoint

Waypoint Distance, Rhumb Line

waypoint location

      WPL,4917.16,N,12310.64,W,003*65
         4917.16,N    Latitude of waypoint
         12310.64,W   Longitude of waypoint
         003          Waypoint ID
           When a route is active, this sentence is sent once for each
           waypoint in the route, in sequence. When all waypoints have
           been reported, GPR00 is sent in the next data set. In any
           group of sentences, only one WPL sentence, or an R00
           sentence, will be sent.

Cross track error, measured

      XTE,A,A,0.67,L,N
         A            General warning flag V = warning
                              (Loran-C Blink or SNR warning)
         A            Not used for GPS (Loran-C cycle lock flag)
         0.67         cross track error distance
         L            Steer left to correct error (or R for right)
         N            Distance units - Nautical miles

Cross-Track Error - Dead Reckoning

      XTR,0.67,L,N
         0.67         cross track error distance
         L            Steer left to correct error (or R for right)
         N            Distance units - Nautical miles