The market on Saturday is worth a visit. Point Lonsdale is close enough by car to get to a surf beach. You can snorkel at The Rip at low tide (ask a local when it is safe), but there isn't heaps to see other than nice sea-vegetation. Lots of food options - check out the local seafood - its fantastic!
Queenscliff is a magnificient coastal town, 30 minutes from Geelong by public transfer. Ferry runs yearly between Queenscliff and Sorrento on the hour. Fishing tours are available and swim with the dolphins also available. Visit Australia's only black light house, visit the lookout of the "rip". Steam trains run on weekends between Queenscliff and Drysdale. Enjoy Fish n Chips sitting on the beach.