The Arch

The Arch is a beginner-friendly dive at Caño Island Biological Reserve off Costa Rica's Osa Peninsula. The site features a natural rock arch formation that creates a dramatic swim-through passage, with the arch walls covered in colorful sponges and small corals. Schools of white-tip reef sharks are commonly found resting beneath the arch and in surrounding sandy areas. The rocky reef around the arch supports diverse Pacific marine life including moray eels, porcupinefish, and large schools of jacks. Easy access and shallow depth combined with reliable shark sightings make The Arch one of Caño Island's most popular and iconic dive sites.