Illinois is a landlocked state and does not offer any ocean or sea diving opportunities. However, there are still diving opportunities available in the state's freshwater lakes and quarries. Here is some information about diving in Illinois, including the best diving spots for beginners and experienced divers, marine life, dive conditions, and cost.

Diving Spots in Illinois:
Illinois' diving spots are primarily located in its freshwater lakes and quarries. One of the best spots for beginners is Haigh Quarry in Kankakee, which features clear waters, a variety of underwater features, including sunken boats and planes, and a training platform for beginners. Another good spot for beginners is Mermet Springs in Metropolis, which also has clear waters and underwater features, including submerged cars and a replica of a sunken city.

For experienced divers, the Lake Michigan Shipwreck Trail is a popular spot. The trail features several shipwrecks and a variety of marine life, including fish, crabs, and other aquatic species.

Marine Life:
Illinois' waters are home to a variety of freshwater fish species, including bass, catfish, and walleye. The state's quarries also have underwater features, including rock formations and sunken objects.

Dive Conditions:
Dive conditions in Illinois' freshwater lakes and quarries can vary depending on the location and time of year. Water temperatures can range from the mid-50s to mid-70s, and visibility can also vary. Divers should consult with certified instructors or dive operators familiar with the dive location and conditions.

Cost:
Diving costs in Illinois can vary depending on the dive location and operator. Most dive operators offer equipment rentals, air fills, and guided dives in package deals, which can range from around $30 to $80 per person per dive, depending on the location and operator.

Overall, while Illinois may not offer ocean or sea diving opportunities, its freshwater lakes and quarries still offer diving opportunities for those interested in exploring underwater features and marine life. Divers should plan carefully and dive with experienced professionals to ensure a safe and successful diving trip.