Given the proximity to the Atlantic and small farms on the mainland, most locally owned restaurants are still heavily influenced by the catch of the day and seasonal field harvests. There are numerous national chain and fast-food restaurants within commercial complexes or malls. Although hard to fathom, relatively few restaurants on Hilton Head are on the water or even have a water view. Although you will find more high-end options, there are still holes-in-the-wall or that serve good-tasting fare and are frequented by locals.
Most restaurants open at 11 and don't close until 9 or 10, but some take a break between 2:30 and 6. Most of the more expensive restaurants have an early dining menu aimed at seniors, and this is a popular time to dine. During the height of the summer season reservations are essential at all times, though in the off-season you may need them only on weekends (still, more and more of the better restaurants require them).