Once you've been scuba diving, you can't wait to strap on an air tank and fins again. There's something alluring about spending time underwater and encountering things that are so different from what you normally see on land.

Once people catch the scuba bug, they'll go to great lengths to pursue it, spending time and money traveling to the Caribbean, the Mediterranean, the South Pacific or South East Africa. Or, they could just go to a nondescript lake in a rural section of southernmost Illinois.

One of America's most unusual dive spots could not be any further from the Atlantic or Pacific oceans. Mermet Springs is located in Vienna, Illinois. This is in the southern part of the state, about 5.5 hours from Chicago by car. The 8-acre lake is located in an old quarry, which is fed by a natural spring. Though most divers stay in the shallower water, Mermet has a depth of 120 feet.

It's a scenic place, but it's often considered flyover country — even to people from the Midwest and Central states. So why do divers from all over the region flock here?

For one, a number of things have been purposely submerged in Mermet's depths. One of the most popular is a motorcycle, which is situated upright so divers can "ride" it. There are also two sunken Cessna aircraft, a rail car, a trailer, a school bus and other surprises  that divers can explore.

The headlining attraction is a Boeing 727. Sitting in 50 feet of water, the aircraft was once part of a Hollywood movie. It was used during the filming of the 1990s action flick "U.S. Marshals," which starred Tommy Lee Jones and Wesley Snipes. Divers can swim along the exterior or through the 120-foot cabin and explore the aircraft through various hatches and windows.

Thanks to its location and its unusual features, it's clear that Mermet Springs is an offbeat dive destination — and we haven't even mentioned one of the lake's most interesting spots. The "Petting Zoo" is a collection of underwater animal statues. The zoo's creatures range from cute and cartoonish to menacing. The most famous inhabitant is Bruce the Shark, a toothy statue that's both frightening and whimsical. Other animals include a lion, an eel and a skunk.

Not all of the creatures in Mermet's waters are inanimate. In fact, some divers come here to see the real underwater wildlife. Schools of large bluegills, common in the Midwest, swim through the lake, and bottom feeders like giant albino channel catfish can be seen. The channel cats are quite large, averaging 40-50 pounds.

The most unusual and exotic fish species in Mermet is the American paddlefish, also known as the spoonbill. These strange creatures usually top 60 pounds by adulthood. Their long snouts, which are kind of shaped like your grandma's spatula, give them a prehistoric appearance. Paddlefish can live for up to 50 years. They often swim together in schools, so though they are rare in the wild, they're easy to see when you're in the lake.

Divers with keen eyes may even spot a freshwater jellyfish, though they are often hard to spot. (Their average size is similar to a quarter.) They are translucent and look similar to their saltwater counterparts, but their tentacles are not strong enough to break through human skin. 

Divers next to an airplane in Mermet Springs

Divers next to an airplane in Mermet Springs.

The dive shop at Mermet Springs offers complete certification courses and advanced specialized training. Diving platforms are used for novice divers to "get their feet wet" before they tackle deeper waters. The dive curriculum offers a natural progression from underwater basics to open water diving to wreck diving, all of which can happen in the same location. Docks and beaches provide easy access to all the dive sites. 

Because it's fed by spring water and rainwater, the lake is relatively clear. Even so, the visibility doesn't compare to the most popular saltwater reef dive spots. Mermet Springs doesn't pretend to offer the same kind of colorful underwater landscapes as those reefs, but it's a unique place that will prove attractive for any diver, especially those based in the Central U.S.

As an attractive freshwater dive site, Mermet proves that you don't need to head to the ocean to enjoy some diving excitement.

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