Ashwin, at the top of the gallery page athttp://www.pbase.com/andrys/bosphorus are two
very good articles with details on this by a travel site in Turkey. Be sure to read those also.
Ashvin,
The Lonely Planet book for Turkey (which we carried around with us) tells you about it.
It is just the regular ferry that takes people to and from work along the strait. Try to get to the Eminonu ferry boat docks (near the Galata Bridge) to buy a ticket and board the ferry at least 20 minutes before it departs, to get a good seat. They are often crowded.
In 2004, they departed at 10:35am, Noon, and 1:35pm. They go all the way up the
Bosphorus to Anadolu Kavagi and then turn around.