Finland
1 region · 4 sites · down to 160 m
In Finland you dive flooded mines and quarries, mainly near Lohja (~60 km west of Helsinki) and near Pieksämäki. The mines are deep and about 4 °C at depth all year. In winter you dive through the ice, with the clearest water of the year.
Map
Not to be missed
- Ojamon kalkkikivikaivos (Ojamo) →
A limestone mine near Lohja to 160 m, only dived at events of the local mine-diving association.
- Montolan kaivos →
A mine to 140 m near Pieksämäki with an intro option, habitats at -6 m and a clear safety document.
- Kaatialan louhos →
A quarry to 39 m in Kuortane that you can dive without booking (everyman's right).
- Paakkilan asbestikaivos →
An old asbestos mine to 30 m at Tuusniemi; free, after notifying the owner.
Regions
Good to know
- You dive Ojamo and Montola only at events of the associations that hold the rights, after registering in their portal; independent diving is not allowed. For Paakkila you notify the owner.
- Montola requires at least Intro to Cave or equivalent for the mine, with thirds, CCR bailout of at least 1.5×, max END 40 m and max one dive deeper than -40 m per day. Ojamo asks for a dive plan, a safety diver on standby and a support team for dives deeper than 60 m or longer than 180 min.
- In summer the pits warm up to ~20 °C, but visibility drops to ≤1 m because of algae, and in autumn sometimes to near zero. Winter gives the clearest water. In winter Ojamo and Montola keep a hole open with pumps.
- Finnish cylinder rules: O₂-clean cylinders are marked 'OXYGEN-SERVICED', mix cylinders carry a NITROX/TRIMIX/OXYGEN label and the fill station records the last periodic inspection. Finnish divers inflate their drysuits with argon.
Tips for safe and enjoyable diving
- Gas: no public trimix or O₂ station is known near Lohja; Arctic Divers in Helsinki fills air. Finnish clubs run their own mix stations for members: ask your event organiser, and bring cylinders with a valid test.
- Drysuit with dry gloves and heating. In the mines, watch for old installations (rails, carts, cables), sharp metal and silt coming down from the ceiling, and never breathe the air in an air pocket.
- Emergency: call 112 and start oxygen. The national hyperbaric oxygen therapy centre is Tyks in Turku; go through 112. At Montola, oxygen and an AED are in the changing room.
- Kaatiala and Paakkila are far from Lohja: plan them as separate trips.
- Rest day: Tytyri Mine Experience in Lohja, a mine museum with an underground gallery about 100 m down.
Certification requirements, configurations and trimix depths are estimates for planning. Always check them locally and dive within your training.
News
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