How do you say "Watch out" in Spanish?

The phrase "Watch out" in Spanish is accurately translated as "¡Cuidado!" This expression is an imperative form that directly conveys a sense of urgency or warning to someone, effectively instructing them to be alert or careful about a potential danger or situation that requires immediate attention.

While "Ten cuidado" also means "Be careful," it is a slightly more indirect suggestion rather than an urgent command. The other options provide either warnings that aren't direct translations of "Watch out" or address completely different contexts—like the legal requirement for wearing a life jacket or instructions related to direction. Therefore, "¡Cuidado!" stands out as the most appropriate and direct translation of "Watch out."