Despite being larger than most other Caribbean islands and receiving more flights from the U.S. mainland, Puerto Rico's diving treasures still remain largely unknown to North American divers. Paguera Wall runs for more than 20 miles out from the island's southwest coast and is home to wall diving - much of it drift diving - that rivals any other in the region. To the east are Vieques and Culebra, which are normally protected from rough seas and not located near any major rivers. That makes for smooth seas and good visibility. Mosquito Bay at Vieques is known for its swirling bioluminesce display during night dives. Fajardo and Humacao also have predictable conditions and are loaded with caves, canyons and tunnels. To the west are the rugged and isolated islands of Mona and Desecheo, which have challenging diving that is similar to that of the Pacific. The voyage from the mainland, however, keeps many divers from going there, so most sites are immaculate. Puerto Rico is an American territory, so travel is familiar and easy. There is a lot to do here, from lazing on a golden beach to exploring historic Old San Juan or the art community in Ponce. San Juan International airport handles flights from virtually every airline servicing the Caribbean, so flights are plentiful and fares reasonable.