I highly recommend staying on Erkan's boat. We had a delightful time & it offered something different to our stay in Istanbul. The boat is exactly as described & there are clean shower/ toilet facilities 100m away from the boat. It is easy to get to Old Town using the ferry network which is very regular & you get to see the city from the Bosphorus which is lovely. Erkan was a great host. He was very flexible with our check in/ check out times, always contactable for local tips / recommendations, and is happy to provide boat trips if you wish. We went on a 4 hour sunset trip which was superb. I would stay there again in a heartbeat :)