The current thread about paying a fine for failing to validate a "water bus" ticket before boarding has me confused. Which tickets and passes must be validated? We bought single-trip tickets ( the €7 ones) and there did not appear to be any way to validate them on the dock. People were tapping various passes on the imob machine but it did not react to our tickets. Then no one checked our tickets so we don't know if we were "legal" or not.