Evidently the captain waited for some time for the weather to improve in Fair Havens. The "Fast" refers to the day of Atonement that fell in the fall each year, sometimes as late as early October. People considered it dangerous to travel by sea between mid-September and mid-November, and the harbors closed for the winter from mid-November to mid-February. Paul had already experienced shipwreck three times ( 2 Corinthians 11:25). He recommended staying through the winter at Fair Havens. A strong northerly or northwesterly wind that frequently came up unexpectedly at that season of the year could blow a ship far from its destination. This is what happened. [source][source][source]
Haenchen noted that Luke recorded11or12sea journeys that Paul took in Acts , beginning at Acts 9:30 and ending with Acts 28:10. He calculated that the apostle traveled at least3 ,000 miles by sea. [1] Thus Paul was a seasoned sea traveler whose word those in authority should have heeded. [source][source][source]