Why spend money on attractions when you can spend a day on the beach for free? After all, the beach is what brings people to town. The golf, dining and shopping are gravy. Start your day by dividing your time between playing and splashing on the beach and cooling off in the hotel swimming pool (shampoo, rinse, repeat). Bring plenty of beach toys to keep the little ones busy, especially shovels. Challenge them to dig up the treasure Blackbeard buried here centuries ago (wink, wink) while you enjoy some quiet time, but that will only hold them for so long. 
Climbing to the Top of the Aruba Tuba — Photo courtesy of Myrtle Waves
When the sun sits high in the afternoon sky, load up the troops and have a splashing good time at Myrtle Waves Water Park. Featuring huge water slides and other aquatic thrill rides, Myrtle Waves provides fun for the whole family. There's a large children's play area for the younger ones, a wave pool and wilder rides for the teens and 'tweens and even a lazy river for the older folks. Myrtle Waves has concessions and picnic tables for a nice break from the water and unlimited drink refills. For a shorter cheaper visit, admission is reduced after 3 p.m. The slowest day of the week is traditionally Sunday, when most visitors are either arriving or departing, if you can swing it.
Take them out to the ballgame at the home of the Myrtle Beach Pelicans, the minor-league affiliate of the two-time AL champion Texas Rangers. Built in 1999, this stadium is considered one of the best minor-league ballparks in the nation. Whether it's catching the next rising star on his way to the major leagues or the between-inning entertainment of sumo wrestling and crab races, the Pelicans put on a show every summer night they're in town. Check for special nightly promotions that feature discounted tickets and giveaways.
Fireworks light up the sky over Broadway at the Beach. — Photo courtesy of Broadway at the Beach
Another free but fun activity for the whole family is fireworks, and the Myrtle Beach sky is filled with them virtually every night during the summer. From the Myrtle Beach Boardwalk, Broadway at the Beach, Barefoot Landing and Market Common, the Grand Strand puts on free fireworks show almost nightly. Check with you hotel front desk or local guides to see when and where the sky will light up. For nights they are shot off on the coast, simply take a few blankets down to the beach and watch them from your backyard.
