Shipwreck diving
Guam isn't instantly thought of as a scuba diving destination, but given its geographic location (it's an island in the Pacific), you can bet there are some excellent diving reefs there. Its water is like a museum, with many wrecks from both World Wars due to its location during WWI and WWII. That explains why this tiny island of barely 544 km2 has almost 20 dive operations. Here is some on the top things about Guam you should know before traveling.
Guam, ironically, features some of the best shipwreck diving locations on the planet, with an undersea armada of freighters, tankers, and bombers. Apra Harbor is a popular shipwreck diving destination. The German merchant ship SMS Cormoran was sunk by an American submarine in World War One, while the Tokai Maru, a Japanese passenger freighter, was sunk by an American submarine in the next generation. The two wrecks are now nestled together beneath the sea, providing access to historic decks and engine rooms for divers.