Exchange your voucher at the ticket office in Kabatas and get access to the boat. The boat departs four times a day from Kabatas ferry station and returns in the afternoon and evening. A Marine Officer will welcome you at the departure pier, help you onto the boat, hand you a Bosphorus cruise plan, and explain to you what you will see during the crossing. Set off for the Princes' Islands, which in Roman, Byzantine, and Ottoman times were used as exile sites and as a monastery region. Today only 4 of the total 9 Princes’ Islands are open to public settlement. Arrive at the most famous and beautiful of these islands called Büyükada, or 'Big Island'. The size of the island is 5.4 km2 and there are 7,300 inhabitants. No traffic except emergency services, carriages and bicycles are allowed there. Spend the day exploring the island at your own pace. Take a walk through the center and get used to the silence that reigns on the island. See the Merkez Eczanesi, a pharmacy from 1870, and feel you have stepped into a time tunnel. Go to Hamlaci Street 4 and see the ruins of the villa which Trotsky lived in exile between 1929 and 1933, writing his autobiography and 3 volumes on the "History of the Russian Revolution". Alternatively, rent a bike and cycle around the island admiring the magnificent old villas lining the streets. Explore the Greek Orthodox St. George Church on top of the island's tallest hill where you can also admire fantastic views of Istanbul, the Marmara Sea, and the neighboring islands. Stop over and visit the former Greek Orphanage, Europe’s largest and the worlds 2nd largest wooden house. Enjoy a delicious lunch in one of the many restaurants around the harbor. Go to one of the public beaches (Halk Plaji) or beach clubs for swimming and sunbathing. If you like hiking, you can also walk around the island on foot. When you have finished exploring, take the return ferry to Istanbul at your leisure. The boat returns from Büyukada (Big Island) to Kabatas ferry station every hour between 4 PM and 8 PM.