Cast off on a catamaran and cruise the waters of Lake Lanier this weekend with the Chattahoochee Riverkeeper. The nonprofit agency is hosting a Memorial Day weekend tour on Chota Princess II. The 40-foot catamaran will set sail at 10 a.m. and return at 12:30 p.m. at Aqualand Marina, 6800 Lights Ferry Road in Flowery Branch. This is the second year of the tour, giving residents who do not have access to the lake the opportunity to relax on it and learn information from environmental experts.