The city's river barge operator is offering visitors to downtown San Antonio a new adults-only river cruise. Go Rio announced the launch of the Mariachi Sip & Cruise this week. The cruise for people 21 and older includes a tour around downtown, live music from a mariachi band, two drink tickets, and a souvenir cup. The ride starts at 7 p.m. on certain dates this month and in May. Tickets for the 50-minute tour cost 60-dollars each.