qualis ubi alterno procurrens gurgite pontus nunc ruit ad terram scopulosque superiacit unda spumeus extremamque sinu perfundit harenam, nunc rapidus retro atque aestu revoluta resorbens saxa fugit litusque vado labente relinquit.
as when the ocean, advancing with alternate flood, now rushes shoreward, dashes over the cliffs in a wave of foam, and drenches the furthest sands with its swelling curve; now flees in fast retreat and in its wash sucks back rolling stones, leaving the sands dry as the shallows retreat.