Lake Oulujärvi by boat: Manamansalo and Ärjänsaari
Lake Oulujärvi is known as the "Sea of Kainuu": 887 square kilometres of open water, long sand beaches and tall sand bluffs in the middle of Finland. Ärjänselkä, east of Manamansalo island, is the largest open expanse of lake water in Finland, so a day on the water here feels more like the coast than the lakeland. Expect day trips from Kajaani to the dunes of Ärjänsaari, short evening runs to Paltaniemi and island hopping in the Metsähallitus hiking area between Manamansalo and Vaala. It is easy going in calm weather and demanding when the wind picks up.
Where can you rent a boat on Lake Oulujärvi?
Private owners around Oulujärvi rent out their own boats. You can see what is available on the page rent a boat at Manamansalo and Lake Oulujärvi. Each owner states in the listing what experience they expect from the renter, and some owners can come along as skipper. That is worth considering if you want to cross the open Ärjänselkä for the first time.
5 boat trips on Lake Oulujärvi
A note on terms: in Finland a "vierasvenesatama" is a guest harbour with berths for visiting boats, and a "retkisatama" is a simple excursion harbour or pier, often with a campfire site and dry toilet.
1. Kajaani to Ärjänsaari: the dune island
From the Kalkkisilta guest harbour in Kajaani it is approx. 10 nautical miles to Ärjänsaari, around an hour each way in a planing boat. Ärjänsaari is a nature reserve being established by Metsähallitus, the state agency that runs Finland's protected areas, and it is part of the Natura 2000 network. Its sand bluffs rise 15 to 23 metres, there are active dunes on the Säippä and Kirkkosäikkä points, and a trail of about 10 km runs round the island. The pier for boaters is at Säippä, next to a tent area and a cooking shelter. A summer café near the main pier can only be reached by water.
Tip: in a small boat, run gently up onto the sand beach and leave the pier to larger boats, as Metsähallitus asks. Next to the pier there is a sunken sand barge marked with buoys. Do not drive or swim over it.
2. Kalkkisilta to Paltaniemi: a short evening run
From Kalkkisilta to Paltaniemi harbour it is approx. 4 to 5 nautical miles, about half an hour. Paltaniemi is a village of fewer than 500 residents, 10 km from Kajaani centre, and its best-known sight is the painted "picture church" (kuvakirkko). Paltaniemi, Kalkkisilta and Koutalahti all have toilet pump-out stations.
Tip: this is a good first outing in an unfamiliar boat because the distance is short and Paltaselkä, the basin off Kajaani, has more islands than the open waters further west. Paltaniemi is mainly a local harbour, so check visitor berths with the City of Kajaani before a longer stop.
3. Ärjänsaari to Manamansalo: crossing Ärjänselkä
From Ärjänsaari to Martinlahti on Manamansalo it is approx. 10 nautical miles of open Ärjänselkä, about an hour. Manamansalo is the largest island in Oulujärvi (7,507 ha) and splits the lake in two. Martinlahti has a home and guest harbour run by the municipality of Vaala, with a service centre, shop, café, sauna and toilets.
Tip: only cross when the forecast is settled for the whole day. Metsähallitus warns that a storm can rise quickly on Oulujärvi and that the big open waters and sudden changes in weather can surprise even experienced boaters.
4. Teeriniemi to Kuostonsaari: ancient bedrock and lean-tos
From Teeriniemi on Manamansalo to Kuostonsaari it is approx. 5 nautical miles, 20 to 30 minutes. Teeriniemi has a guest pier next to the camping area and a café. On Kuostonsaari there is a pier and a lean-to (laavu) at Kuoston Kulma, a second lean-to at Kuoston Säippä and a trail from one end of the island to the other. The rock here is gneiss about 2,700 to 2,600 million years old, part of the oldest continental crust in the EU. The same rock can be seen at Kilonniemi on Manamansalo.
Tip: Martinlahti to Teeriniemi is only approx. 3 nautical miles. Along Manamansalo's north shore, waves and ice have cut sandy bluffs where sand martins nest. You see them best from close to the shore.
5. Vaala, Honkinen and Kaarresalo: an island loop on Niskanselkä
From Sahanranta in Vaala, at the outlet where the Oulujoki river leaves the lake, a loop via Honkinen and Kaarresalo is approx. 14 nautical miles and takes 2 to 3 hours with stops. Both islands have a hiking-area pier and a kota (a round shelter with a fireplace), and Kaarresalo also has a campfire site and a toilet. Sahanranta has a guest harbour, kiosk, sauna and swimming beach, and Vaala centre is 500 metres away.
Tip: Niskanselkä is one of Finland's widest open lake basins, and sandy shoals line its edges. Follow the marked routes and keep a chart or chart app open.
| Route | Distance | Time | Highlight | Suits |
|---|---|---|---|---|
| Kajaani – Ärjänsaari | approx. 10 nm | about 1 h each way | dunes, sand beaches, summer café | day trips, families |
| Kalkkisilta – Paltaniemi | approx. 4–5 nm | about 30 min | picture-church village | evening run, beginners |
| Ärjänsaari – Martinlahti | approx. 10 nm | about 1 h | Finland's largest open lake water | experienced, calm days |
| Teeriniemi – Kuostonsaari | approx. 5 nm | 20–30 min | ancient gneiss, lean-tos | hikers, overnight stays |
| Vaala – Honkinen – Kaarresalo | approx. 14 nm | 2–3 h | Niskanselkä islands | anglers, island hopping |
Distances are estimates from the map. Always navigate with a chart or a chart app.
Rules and safety on Lake Oulujärvi
- Oulujärvi hiking area (Metsähallitus): Everyman's rights apply. You may camp on the islands, but on Manamansalo only at official rest sites. You may stay overnight in an excursion harbour and keep your boat there for up to two days. Fires are allowed only at marked fireplaces and never during a forest-fire warning, except in shelters with a chimney. Keep pets on a leash and take your rubbish home. See the hiking area's rules (in Finnish).
- Ärjänsaari: You may not enter the bird nesting area on Kirkkosäikkä, the island's eastern tip, from 1 May to 31 July. Camping is allowed only at the Säippä tent area. The berths on the south side of the Säippä pier are reserved for charter boats. The north side has eight mooring buoys, and for stern-buoy mooring you need fenders and a stern line of about 20 metres with a buoy hook. There are sudden drop-offs and currents on both sides of the points. See the Ärjänsaari rules.
- Bird islets: The Oulujärvi bird islands (Natura 2000, 12 islets including Tiirikari, Reimikari and Purjekari) are nesting sites for gulls, terns and black-throated divers. Do not land on them during the nesting season.
- Everyman's rights: You may boat, swim and stay temporarily on shores, but not in private gardens or too close to homes. Making a fire is not part of everyman's rights. Finland's Water Act allows temporary anchoring.
- Toilet waste: Discharging toilet waste from a boat is prohibited on all Finnish inland waters. Pump-out stations are at Kalkkisilta, Koutalahti and Paltaniemi.
- Who may drive: Finland has no compulsory licence for leisure boats up to 24 m. A motorboat that must be registered (engine of 15 kW or more, or a hull of 5.5 m or longer) may only be driven by someone aged 15 or over. Read more about the boat licence rules in Finland. According to Traficom, the limit for drunk boating is 1.0 per mille.
- Water level and waves: Oulujärvi is regulated, and the water level varies by 170 cm a year on average, so shoals and beaches change over the summer. Metsähallitus says that storms on Oulujärvi call for a seaworthy boat, so do not head out onto the open basins in a boat that is too light.
Best time for a boat trip on Lake Oulujärvi
The best time for boating is June to August, and Midsummer is the busiest time in the hiking area. The average surface water temperature at Manamansalo has been 14.8 °C in June, 18.4 °C in July and 16.4 °C in August, which makes July the best month for swimming. Kajaani's harbour season runs from 1 May to 15 October. The century-old steamship S/S Kouta runs public cruises in summer, including a day cruise to Ärjänsaari. Check timetables and the current notices for the nature sites before you go, for example about the condition of the piers on luontoon.fi. The well on Ärjänsaari can run dry in hot weather, so bring your own drinking water.
FAQ
How big and deep is Lake Oulujärvi?
According to the Finnish Environment Institute (Syke), Oulujärvi covers 887 km², has an average depth of only 7.6 metres and a maximum depth of 35 metres. There are 665 islands, which is few for a lake this size, so there is little shelter from the wind on the open basins.
Why is Oulujärvi called the Sea of Kainuu?
The open basins, sand beaches and dunes look like the coast, and seabirds such as the Caspian tern and even the Arctic skua are seen on the lake.
Can you camp or sleep on your boat on Oulujärvi?
Yes. You may stay two days in the hiking area's excursion harbours and camp on the islands under everyman's rights. On Manamansalo camping is allowed only at rest sites, and there is a camping area next to the guest pier at Teeriniemi. On Ärjänsaari, tents are allowed only at Säippä.
Are there cruises on Lake Oulujärvi?
Yes. The steamship S/S Kouta, which is more than 100 years old, sails from Kalkkisilta in Kajaani in summer. Its trips include day cruises to Ärjänsaari and evening cruises on the lake.
Do I need experience to take a boat out?
No licence is required, but the owner may ask about your experience. Only head for the big open waters once you can handle the boat in a chop, or ask the owner to come along as skipper.
To compare Oulujärvi with other inland waters, read about the best lakes for boating in the Finnish lake district and our guide to Lake Saimaa.
