Fagles translation

skimming the waves, and over the swells they came,
dolphins leaving their lairs to sport across his wake,
leaping left and right - well they knew their lord.

οἱ δ᾽ ἄρ᾽ ἐπ᾽ οἴδμασι βῆσαν, ἐπὶ κλύδωνας ἰόντες, δελφῖνες δ᾽ ἐκ βένθεσφι λιπόντες κευθμῶνας ἕποντο, σκίρτων ἔνθα καὶ ἔνθα· ἄνακτα γὰρ ἔγνων ἑόντα