The word "aguas" literally means "waters" in Spanish. However, in Mexican slang, it's commonly used as an interjection meaning "watch out!" or "be careful!"
In this song, it's used to warn about potential dangers or to signal that something illicit is happening, often in the context of drug trafficking. The phrase "por debajo del agua" (under the water) further emphasizes the secretive and hidden nature of their activities, making "aguas" a key word for understanding the song's street-smart tone.
"Aguas" opens with Luis R Conriquez checking the time on jewelry he doesn't need: "Un pinche Rolex Daytona Que nomás lo uso para ver la hora" (A damn Rolex Daytona / That I only use to check the time). That's the whole song in one line: expensive things worn like they cost nothing. He name-drops his Motorola and his Balenciaga, then says he stays out of photos: "No me gusta salir en las fotos Pocas veces han visto mi rostro" (I don't like being in photos / They've rarely seen my face). Neton Vega and Rey Quinto take the second half, each grabbing a verse to brag about the crew riding with him and the guns he keeps close.
The hook runs on slang that won't translate word for word. "Y aguas que le metemos aguas Por debajo del agua" (And watch out, we'll give them water / Under the surface) uses "aguas" the way it gets used across Mexico, as a warning rather than the liquid, then piles on talk of tires, flour, and "Los cueritos de rana" (The frog skins). It's the coded language this style of corrido runs on, and the song never explains any of it. It just repeats the chorus like a joke only the crew is in on.