7/11: Paddling: Semana Nautica Kardboard Kayak Races Watch as teams of up to four display their engineering skills, as well as athletic ability, as they assemble their kayaks with two sheets of cardboard and adhesive tape in one hour and then attempt to paddle them out to a buoy and back to the beach before they disintegrate. Participation fees benefit the S.B. Maritime Museum. Noon-3pm. West Beach (across from Sambo’s Restaurant, 216 W. Cabrillo Blvd.). Admission: free; registration fee: $30-$40. Call 962-8404 x115 or visit sbmm.org.