Dive Site Guide · Ottawa, Ohio
Gilboa Quarry
Gilboa Quarry is one of the most diver friendly freshwater sites in the Midwest. Clearer water than many Chicago area quarries, easy entries, on site fills, and plentiful underwater attractions make it a dependable training and practice location. The notes below cover hours, check in, fills, camping, and simple ways to move around the site efficiently.
Site Snapshot
- Type
- Freshwater quarry
- Hours
- Generally 9 am to 5 pm; extended hours Friday and Saturday
- Temperature
- About 72 F on the shallow side above the first thermocline near 20 ft in mid summer
- Fills
- Air about $10; banked Nitrox 30 about $12; oxygen for technical and rebreather fills
- Fill workflow
- Buy tokens in the office; drop off and pick up at the fill station
- Instructor support
- Active class instructors dive free and receive free air or Nitrox fills
- Rentals
- Basic rental equipment available
- Camping
- Tent and RV options
- Entry
- Large docks with submerged platforms at the stair edges
- Site features
- Shallow and deep sides; many attractions at a range of depths
- Gear transport
- Metal rolling carts available
- Plan Your Visit
Things to Know
- Often better visibility than local Chicago quarries, even on busy weekends with hundreds of divers.
- Generally open from 9 am to 5 pm with extended hours on Friday and Saturday.
- Shallow and deep sides. In mid summer the shallow side is about 72 F above the first thermocline near 20 ft.
- Onsite air fills about $10 and banked Nitrox 30 about $12, plus oxygen for tech and rebreather fills. Buy fill tokens in the office.
- Instructors with an active class dive free and receive free air or Nitrox fills.
- Basic rental equipment is available.
- Tent and RV camping options are available.
- Excellent entries with large docks and submerged platforms at the stair edges that work well for pre and post dive debriefs.
- Many attractions at a range of depths.
- For fills: buy a token in the office, hang the token on your valve, place the tank on the Drop Off side outside the fill station door, then pick it up from the Pick Up side. Weekend lines build after noon, so plan ahead.
How to Check In
- Before you arrive, complete and submit the liability forms online.
- Enter through the gate and bear right as you pass the first buildings on your right. If traffic is light you can stop briefly at the main office. Otherwise, park in the first lot on your left.
- Go into the office, pay your daily rate, and register. You will receive a wristband color coded for your stay.
- Ask about current reservations and where to park. Guidance changes with crowd levels.
- Use the metal rolling carts, usually about 50 available, to move tanks and gear between parking and entry points.
- Go diving.