Translation of "Swell" in Spanish

This is going to be swell.

Ésta si que va a ser buena.

My hand would swell up and the pain would come back.

mi mano se hincha y el dolor regresa.

Perhaps she's trying to mimic kelp or algae moving in the swell...

Tal vez intenta imitar algunas algas moviéndose con el oleaje.

That is protected with a big piece of kelp forest, 'cause the forest itself actually dampens the swell.

protegida con un gran bosque de algas kelp. Porque el bosque en sí amortigua el oleaje.

"Everything's well, everything's swell," he told me with a sing-song voice, and I had no choice but to believe him.

«Todo va bien, todo va bien» me dijo con una voz cantarina, y no me quedó más remedio que creérmelo.