Two random trips bring on a strange coincidence

With my family we flew to Skiathos and boarded our sailing boat chartered for the week. We set off for one of the islands, stopped for lunch and eventually moored in a harbour for the night. This pattern was repeated on the next two days. We chose our destination each morning depending on wind direction and sea conditions as my wife is apprehensive of loosing site of land. On the fourth day sitting in a taverna on another random island and in a random choice of resturant (one of many), a young woman came to sit on the opposite side of the block of chairs. This was Sue from the office where I worked, neither of us knew that the other was on holiday, nevermind on a Greek island. She and her husband had taken a last minute flight, booked a room at the airport, gone to the harbour the next morning and took the next ferryboat leaving, getting off at its destination, getting a room and repeating this each day. So how did we end up same island same taverna at the same time?