Latitude

The position of the boat on the globe relative to the north/south axis of the world. By crossing a line of latitude with a line of longitude you can fix a boat’s position anywhere in the world.

Longitude

The position of the boat on the globe relative to the east/west axis of the world. By crossing a line of latitude with a line of longitude you can fix a boat’s position anywhere in the world.

DTF

Distance To Finish; the great circle distance from the boat to the finish line at the time of the six hour poll.

DTL

Distance To Leader; the great circle distance from the boat to the leader at the time of the six hour poll.

DTLC

Distance To Leader Change; the difference between the distance from the boat to the leader taken at the time of the last six hour poll, and the distance from the boat to the leader at the previous poll.

A negative value indicates a loss on the leader.

CMG

Course Made Good; the average course steered over the period of the past six hours up to the time of the last poll.

SMG

Speed Made Good; the average speed of the boat through the water over the six hour period before the last poll. Speed, a calculation of distance over time.

VMG

Velocity Made Good; the average velocity of the boat towards the finish over the entire leg. In other words, Total leg distance minus distance to finish, divided by elapsed leg time. Boats may decide for tactical reasons, and when sailing to windward, to sail a less than direct course to the finish. VMG will show the different potential between the courses the boats are sailing as they strive for the finish line. Velocity, a vector quantity whose magnitude is a body's speed and whose direction is the body's direction of motion.

ETA

Estimated Time of Arrival; an estimation of the arrival time of the boat, computed from its VMG and the Distance To the Finish. GMT; Greenwich Mean Time, the base time for all nautical chronology.