Buy a ticket and join the fans at a game at Marguerite Aquatic Complex. If there's nothing scheduled while you're in town, you might like to check if there's a tour of the facilities.
This sporting facility is one of the highlights in Mission Viejo. However, it's not the only place worth visiting in the area. Once you've paid the entrance fee and spent some time at Marguerite Aquatic Complex, have a look at nearby Irvine Spectrum Center, Saddleback Church and The Shops at Mission Viejo as well.