There are two tour bus operators in Riga. A yellow bus (this one) and a red bus. Both are hop-on hop-off. Our hotel offered a discount on the Yellow bus system and we signed up for their two day pass since we were starting in the afternoon. First day was excellent. The headsets offer multiple languages and are synched with the bus location. The next day we wanted to do the remainder of the tour so we went to where we had been left off the previous day, which also happened to be their starting location. We waited for 30 minutes pass the announced starting time. Then went to see the Occupation Museum (right next door). Came out at the next starting time, no bus, again. Meanwhile, the driver of the red bus had seen us standing around waiting. He came over and invited us onto his bus, without asking for a fee, even though we had paid for his competition. Very nice man and we got to see the section of town that we had missed the previous day.