Cape Cod’s present and past shucking champs return to compete in the two-day Oyster Shuck-Off at the annual Wellfleet OysterFest Oct. 16-17. Last year’s champ, James Grey, faces serious competition from at least 20 other entrants, among them Barbara Austin, winner the previous two years. When opening each tray of 24 local oysters, entrants must remember that the mollusks’ final appearance on the half shell counts as much as speed. The top prize is $1,000. Audience members bid on the opened oysters. The rest of the 9th annual fest revolves around a 5-K road race, arts and crafts fair, food tastings and talks, demonstrations by American oyster shucking champion William “Chopper” Young Jr., walking tours, music, and a spaghetti supper. (See website for required reservations and fees for some programs.) The festival is sponsored by SPAT, a nonprofit organization that promotes the local shellfish industry. 9 a.m.-5 p.m., Main Street, Wellfleet, Mass. Visit the website for schedule and parking information. No pets allowed.