Capitano means "captain" in Italian. While it's a common word, its appearance in this song is quite striking and creates a powerful, unexpected image.
In the lyrics, the singer talks about a ship arriving in port, loaded with memories. However, the "capitano" of this ship delivers a surprising and somewhat dark message: "il suo capitano mi ha detto di dirti che è morto" (its captain told me to tell you that he's dead). This twist makes the word memorable and adds a layer of mystery and intrigue to the song's narrative.
The singer is asking someone to wait. He opens with "Chiamami fra un po' di tempo" (Call me in a while) and "Magari sto meglio" (Maybe I'll be better), so he is still hurting and not ready to talk. Even his answers are hedged: "Magari ti dico magari" (Maybe I'll tell you 'maybe') turns the word maybe into the whole reply, and he imagines the phone ringing while "non sento" (I don't hear it).
The chorus switches to an image of a ship. "La nave che aspetti è nel porto" (the ship you're waiting for is in the harbor) and it is "carica del tuo ricordo" (loaded with memories of you). Its captain has sent word that he is dead, yet the singer knows he "aspetta nascosto / E disegna il tuo volto" (waits hidden / and draws your face). The love is still there, hidden, and "Amami quando è il momento" (Love me when it's time) asks only that the other person come back at the right moment.