Megijima Beach, also called Onigashima Beach, is generally safe for swimming during summer months when weather is calm. The white sand beach has a gradual entry into the water, making it family-friendly. However, lifeguard availability may be limited, so exercise caution and check local conditions. The Seto Inland Sea here typically has mild waves, but currents can vary. Jellyfish may appear in late summer. The beach is well-maintained and popular with families, indicating good safety standards. Always supervise children and avoid swimming during rough weather or high winds.

The best time to visit Megijima Beach is between late June and early September for swimming, with July and August offering warmest water temperatures. Spring (April-May) and autumn (October-November) are excellent for exploring the island's art installations and hiking trails without crowds, though swimming may be too cool. The Setouchi Triennale art festival, held every three years, brings extra visitors but also special exhibitions. Weekdays during summer offer beautiful beach weather with fewer crowds than weekends. Early morning visits provide excellent photography light on the distinctive white sand.

Megijima Beach is accessible via ferry from Takamatsu Port, with regular services taking approximately 20 minutes. Ferries depart from Takamatsu Port near JR Takamatsu Station several times daily, with increased frequency during summer and festival periods. Check the Meon ferry schedule in advance as times vary seasonally. Once on Megijima Island, the beach is within walking distance from the ferry port, roughly 10-15 minutes on foot. The island is small and walkable. Return ferry times should be confirmed to avoid getting stranded, especially during off-peak seasons.

Megijima Island has limited but charming food options, including small cafes and restaurants serving local seafood and udon noodles near the port and beach area. Opening hours can be irregular, especially off-season, so bringing snacks is wise. Guesthouse accommodation is available on the island, offering a quiet overnight experience, though options are limited and should be booked ahead during summer and art festival periods. Many visitors day-trip from Takamatsu, where extensive dining and hotel choices exist. Vending machines and small shops provide basic supplies on the island.

Megijima Beach is nicknamed Onigashima Beach because the island is legendary as the 'Demon Island' from the famous Japanese folktale Momotaro. The island features caves said to be demon dwellings, adding mythological charm. The beach's distinctive white sand and clear water make it highly photogenic and Instagram-worthy. During the Setouchi Triennale, contemporary art installations dot the island, combining culture with beach relaxation. The combination of folklore, art, accessible island setting, and beautiful beach makes Megijima unique among Takamatsu's coastal destinations, offering more than typical beach experiences.