Adam Clarke on Acts 27:39

They knew not the land - And therefore knew neither the nature of the coast, nor where the proper port lay.

A - creek with a shore - Κολπον, Sinum, a bay, with a shore; a neck of land perhaps on either side, running out into the sea, and this little bay or gulf between them; though some think it was a tongue of land, running out into the sea, having the sea on both sides, at the point of which these two seas met, Act 27:41. There is such a place as this in the island of Malta, where, tradition says, Paul was shipwrecked; and which is called la Cale de St. Paul. See Calmet.