Mermet Springs

About this dive site

Mermet Springs is a unique dive site located in Southern Illinois, within an 8.5-acre spring-fed quarry. This quarry offers a fascinating underwater experience due to its consistently warm temperatures and abundant freshwater life. Water visibility ranges from 15 feet to over 60 feet, providing excellent viewing conditions. Temperature fluctuates with the seasons; expect cool temperatures at depth during winter, ranging into the low 40s, while the water warms up considerably above the thermocline in the summer, reaching the mid-80s. The site provides essential amenities including warm water showers, full restrooms, and on-site tank fills alongside covered pavilions for divers' convenience. A highlight of Mermet Springs is the presence of paddlefish – a rare sight! Divers can also explore various underwater structures, such as the iconic 727 aircraft from the film *US Marshals*.