As we were driven to and fro (διαφερομενων ημων). Genitive absolute with present passive participle of διαφερω, old verb to bear different ways (δια=δυο, two), this way and that. Continued to be tossed to and fro in the rough seas. It would seem so to those on board. It does not necessarily mean that the wind had changed. The fourteenth night is reckoned from the time they left Fair Havens.

In the sea of Adria (εν τω Hαδρια). Not the Adriatic Sea as we now call the sea between Italy and the mainland of Illyricum, but all the lower Mediterranean between Italy and Greece. Luke's usage is like that of Strabo.

Surmised (υπενοουν). Imperfect active indicative of υπονοεω, inchoative, began to suspect.

That they were drawing near to some country (προσαγειν τινα αυτοις χωραν). Infinitive with accusative of general reference in indirect assertion. Προσαγω is here used intransitively and Luke writes from the sailor's standpoint that a certain land was drawing near to them (αυτοις, dative). The sailors heard the sound of breakers and grew uneasy.