We stayed on Derk's boat for a long weekend in Amsterdam. It was great! Sadly we didn't meet Derk, as he was on holiday, so we didn't get to learn the history of the boat as some other guests have. But he left us in good hands with a friend, who met us at the boat to give us the keys and show us around. Rain on the boat's roof is the most soothing thing at nighttime... slept like a baby!!!