It's almost hidden in plain sight. Despite having some of the best wall and wreck diving in the Caribbean St. Croix, the largest of the three main U. S. Virgin Islands, gets overlooked in most USVI diving itineraries. It's also, topside, perhaps the most authentic of the three virgins with a National Heritage Trail that takes you right into the pulse of the island, its people and its amalgam of cultural influences. But the best part for divers drops straight down from the north coast of the island.

Near the only place that Columbus is said to have set foot in America (in 1493), called Salt River (it's also an ecological preserve), are the dive sites of Salt River Canyon East and West. Here, the lush walls drop off several thousand feet. On either side the walls are thickly decorated with sponges, gorgonians and sea fans. Loads of marine life call this place home, too.

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West Wall (one of the named sites) is riddled with swim-throughs, canyons and cuts in the reef. You'll encounter large stoplight parrotfish, angels, several species of grouper, blackbar soldierfish in the shadows and horse-eye jacks off the edges. Always keep an eye to the blue on these dives. Sea Turtles like to come in and nosh on the sponges. Dolphins frequent the area, and when they're close you'll hear their clicks, chirps and squeals reverberating in the water column.

At other places off the north coast of St. Croix, walls start in as little as 20 feet of water and drop off to almost 13,000 feet. They're absolutely vertical. Like peering down the edge of a skyscraper.

Besides the wall diving, there's plenty of dives for all skill levels. And the best part is it really is a secret. Who knows why, but one things for sure. You'll have more of the reef all to yourself, you'll be able to brag that you dived some of the best walls in the world and no one will suspect you've just come back from the US Virgin Island of St. Croix.