How can you tell if two sailboats are racing?

[Urban Hermit]

They're in sight of each other and going roughly the same direction.

[Jim in TC]

My sailing dictionary defines racing as a "popular nautical contact sport."

[soilgod]

yes Urban, any 2 sailboats in close proximity are racing.  And both are commenting on the others sail trim.  The winner is the craft that gets upwind and blankets the wind of the loser.  Time to pop a cold one.  LOL