Samos is a mountainous island in the SE part of the Aegean Sea off the coast of Asia Minor. It is 27 miles long (E-W) and about 14 miles wide. The island is separated from the mainland by a strait of one mile.
Paul and his companions stopped at, or passed near, Samos on the return from his third journey.
Sailing from there [Mitylene], we arrived the following day opposite Chios; and the next day we crossed over to Samos; and the day following we came to Miletus. (Act 20:15 NAU)
English versions do not make it clear whether Paul stopped at Samos or came within sight of the island. These comments by Floyd Filson might be helpful.
Paul’s ship…either ‘touched at’ and anchored overnight at Samos (so RSV, though this is an unusual meaning for parebalomen) or ‘came near’ to Samos and passed by it on the E or the W to anchor for the night at Trogyllium. (Interpreter’s Dictionary of the Bible. IV:197)
Here is a view of the eastern end of Samos as a ship passes through the most narrow part of the strait between the island and the Turkish mainland.
Paul may not have visited Samos, but it is clear that he came very close.