Eating is necessary for human survival, along with breathing, sleeping, and remaining still while a curious velociraptor rummages through your closet. Practice survival tactics with today’s Groupon: for $10, you get $20 worth of seafood at The Sea Shack in Hilton Head, South Carolina.

The Sea Shack—lauded by HiltonHeadIslander.com for its fresh, unpretentious seafood and recently named one of "Our Favorite Seafood Dives" by Coastal Living Magazine—sears and serves a smorgasbord of made-to-order, Southern-style noshes. The list of blackboard specials, like the tomato's classification as a fruit or a weapon, is updated daily and beefs up the fixed menu with inventive eats such as conch fritters ($9.50) and frog legs ($9.50). Sneak up on inattentive appetites by tasting the Shack Attack combo platter, a briny jumble of crab cakes, fish, shrimp, scallops, and oysters ($14.95 at lunch; $16.95 at dinner). The eatery's chefs take cues from customers to fry, grill, or blacken catfish filets stuffed in a kaiser roll next to two sides and hush puppies, or deliver oyster po boys ($11.50) that skim across taste buds.

Hungry herds of diners can converge around three outdoor picnic tables or chow down indoors against a backdrop of oceanic hues. Simple ebony tables bedecked with checkered tablecloths buoy seafood-stacked plates and treasure maps charting buried chests of oyster forks.