Taking the local ferry in Istambul - Europe to Asia

Istambul is a city divided between two continents, by the Bosphorus strait. Sometimes, the world seems too big, but in days like this, when crossing between Europe and Asia (Karakoy - Kadikoy), takes only 15 minutes on a ferry, it seems too small.
Once in Istanbul, there is no need of booking expensive touristic tours along the Bosphorus, you can simply use your Istanbul card, top it up, and take as many ferries as you want. That includes from Europe to Asia and Princess Islands. In fact, this is a much better way to see things, just as locals do.
On the boat you can have a tea or a snack while you watch the amazing views of both sides.
It is really worth to travel to Kadikoy on the Asian side and spend a day there. The price of the ticket was just 3TLeach way!!