Tally-ho

Tally-ho dates from around 1772, and is probably derived from the French taïaut, a cry used to excite hounds when hunting deer.

[2] The cry was made by the huntsman on catching sight of the fox to alert other members of the hunt.

It has been used in similar circumstances for quite different quarries: It was used by RAF fighter pilots in the Second World War to tell their controller they were about to engage enemy aircraft.

"Tally-ho" is also used by NASA astronauts in audio transmissions to signify sightings of other spacecraft, space stations, and unidentified objects.

[6] In the United States, "tally-ho" can describe a large coach or a light passenger vehicle without roof or sides used for sight-seeing.