Slurp down Bay oysters, dine on delicious food, enjoy drinks at the open bar and bid in silent and live auctions at the South River Federation’s Annual South River on the Half Shell fundraiser to benefit the Federation’s work to protect, preserve, restore and celebrate the river. 6-10pm at Homestead Gardens, Davidsonville. $85 w/discounts; rsvp: 410-222-3802; www.southriverfederation.net.