Bosphorus Tour
Bosphorus tour is definatelly a must see attraction in Istanbul suitable for whole family. It’s a unique experience to see both banks of Asia and Europe at the same time, enjoying fresh sea breeze and exploring beauty of Istanbul. By joining boat trip you have a great chance to see lots of citys sightseens in a short time period. According to your wish you can plan Bosphorus tour from different points of Istanbul and at suitable time.
Most popular tour points are Eminonu and Ortakoy in European side. Please note that from May to September the frequency of tours is more high.
There are many companies offering different types of Bosphorus tours - short and long time crouises, lunch / dinner boat tours, group and private Bosphorus excursions:

Bosphorus Tours
All tours Istanbul

Although you have chance to make your boat trip very special you should know that if you come to Ortakoy or Eminonu without planning and booking you can join a 45 min Bosphorus tour by paying only 15 TL per person (free for children upon 6 y. o.). Tours are offered every hour daily from 11:00 to 17:00 from May to September.