Dive-site story
Mermet Springs is a purpose-built freshwater quarry training facility in southern Illinois, famous for submerged training attractions and resident freshwater fauna. Divers navigate an extensive underwater trail system connecting submerged wrecks, including a complete Boeing 727 fuselage used in the movie U.S. Marshals, multiple emergency vehicles, a school bus, and suspended training platforms. The quarry walls plunge steeply into a silt-bottomed basin, featuring distinct thermoclines that change drastically as you descend.
Exploring the intact Boeing 727 fuselage resting along the quarry wall
Hand-feeding docile spoonbill paddlefish and large bluegill along safety stops
Suspended training platforms and well-marked underwater navigation lines
Sunken work vehicles including a fire engine, ambulance, and semi-truck trailer
Location
Use the map to plan with your operator and confirm the exact entry point on the day.
Seasonality
Late spring through autumn offers comfortable surface temperatures and full on-site facility operations.
Marine life
| Species | Likelihood | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| American PaddlefishPolyodon spathula | Common | ||||||||||||
| Channel CatfishIctalurus punctatus | Common | ||||||||||||
| BluegillLepomis macrochirus | Common | ||||||||||||
| Largemouth BassMicropterus salmoides | Common | ||||||||||||
| Freshwater JellyfishCraspedacusta sowerbii | Seasonal |
Marine forecast
