Maui has more safe swimming beaches than any other Hawaiian island, and most of them are on the leeward (west) coast, a run of sand most of the way from the Gold Coast (Kihei-Wailua) in the south to Lahaina-Ka'anapali in the north. And all along this coast are condos, cars, and resorts.
To check out the more-serene locals' scene, cross the island to the windward coast. Kanaha Beach Park (above) is laid back, in spite of its proximity to the airport in Kahului. You can take a short stroll to privacy in Spreckelsville, or hang around the beach park to watch some of the world's best kite-boarders and windsurfers.
Just up the road toward Paia is one of the best locals' haunts in the Islands: Baldwin Beach Park. Families and local boys have been chillin' and surfing here since Baldwins beginnings in the late 1800s as a spot for sugar cane workers to relax. The place embodies Hawaiian style living, especially in the late afternoons and early evenings. A few hundred yards down the sand from the beach park is Baby Baldwin Beach, a protected swimming oval with safe swimming even on days when the surf's up (you can also drive to Baby Baldwin).