Grenland by boat: Porsgrunn, Brevik and the Telemark Canal
Grenland, in Telemark in southern Norway, is one of the few places where a boat trip can start on a river in a town and end among the skerries on the same day. From Skien the river runs past Porsgrunn and out the Frierfjord to Brevik, one of Norway's best-preserved sailing-ship towns. Beyond lie the islands of the Langesundsfjord, Langesund and the Langøya nature park. Head the other way and the Telemark Canal starts in Skien, lifting boats inland through historic locks.
Where can you rent a boat in Grenland?
Private owners rent out their own boats across Grenland, from the river towns to the coast. Browse boats for rent in Porsgrunn, boats for rent in Skien, rent a boat in Brevik and boats for rent in Langesund. Each owner states their own licence and experience requirements, and some owners can come along as skipper. If you plan to take the boat into the Telemark Canal, agree it with the owner first.
6 boat trips in Grenland
The river from Skien to Porsgrunn
Approx. 5 nautical miles from Langbryggene in Skien to Østre Brygge in Porsgrunn, about an hour each way at an easy pace. You see both towns from the water and pass under Menstadbrua (27 m clearance). In Skien, Langbryggene has 35 guest berths right in the centre by the fountain. In Porsgrunn you can moor at Østre Brygge, with up to 16 berths with power and water on the floating pier and 22 alongside berths without, or at the Down Town pier.
Tip: the speed limit on the Skien river (Skienselva) is 6 knots. Porsgrunn bridge has only 8 m clearance and Frednes bridge 13 m when closed. Most motorboats pass underneath, but a sailboat has to ask for an opening on VHF channel 12, and the bridges do not open for leisure boats 07:00–09:00 and 15:00–17:00 on weekdays.
Porsgrunn to Brevik through the Frierfjord
Approx. 6 nautical miles from Porsgrunn to Brevik, 30–45 minutes. The route runs out the Frierfjord past the industrial areas to Brevik at the tip of the Eidanger peninsula. Brevik became a town in 1845 and is counted among Norway's best-preserved sailing-ship towns, with narrow streets and old wooden houses. Brevik Gjestehavn at Sjøloftet in the inner harbour has 40 guest berths, showers and washing machines, and Restaurant Sjøloftet sits by the guest pier. A gjestehavn is a guest harbour: public berths for visiting boats, usually paid per night.
Tip: the limit is 5 knots in Brevik and 8 knots in Breviksstrømmen, the strait that big ships also use. Keep well clear of them.
Island hopping off Brevik: Sandøya, Løvøya and Bjørkøya
Approx. 1–3 nautical miles from Brevik, half a day or more. Sandøya lies just off Brevik, with family-friendly swimming spots and good footpaths, and a footbridge to Løvøya with small coves and smooth rocks. Bjørkøya is known for its coastal path, viewpoints and swimming coves, and you may pitch a tent on its public recreation areas. Siktesøya in the Langesundsfjord is also on Visit Telemark's list of islands for island hopping.
Tip: Sandøysundet has a 5-knot limit. The islands have many cabins and private jetties, so use public piers and recreation areas, and only anchor where it is allowed and safe.
Brevik to Langesund and Langøya
Approx. 4 nautical miles from Brevik to Langesund, 20–30 minutes. You follow the Langesundsfjord south towards the open sea. Langesund guest harbour has 80 m of pier in the town centre with water and power. Day visits are free for up to four hours, and berths cannot be booked in advance. Showers and toilets are at Kongshavn guest harbour. Just across the sound lies Langøya, a flat island 2.9 km long that was given to the people of Bamble as a nature park in 1947 and is now a protected landscape area because of its rare plants. Langøya guest harbour is open from 1 April to 30 September. From there you can walk the 4.5 km coastal loop, swim and see Langøytangen lighthouse, dating from 1828.
Tip: the limit is 5 knots in Langesund. Out in Langesund bay you meet the open sea, so check wind and waves before going round Langøya.
Stathelle and a Brevik harbour loop
Less than half a nautical mile across the sound from Brevik, and a nice short evening trip. Stathelle guest pier lies along the quay in old Stathelle, just before Breviksbrua (45 m) towards Porsgrunn, with 10 berths with outriggers and a 20 m floating pier with power and water. Mooring is free until 20:00. Combine it with a loop round Brevik harbour.
Tip: Breviksstrømmen is the shipping lane into Grenland. Look around carefully before you cross, and don't drift in the channel.
The Telemark Canal from Skien
The Telemark Canal (Telemarkskanalen) starts at Skien lock, with a 5 m lift and a single chamber. Hjellebrygga guest harbour lies just past the lock, and approx. 3 nautical miles further up come the Løveid locks at Skotfoss, with 7 waiting berths and showers. Then Lake Norsjø opens up. The whole canal has eight lock sites with 18 chambers and runs 80 km to Notodden and 105 km to Dalen. The canal allows 3–4 days for a Skien–Notodden round trip and at least a week for Dalen and back. With a rented boat, a day trip through Skien lock and up to Norsjø is a good alternative.
Tip: in 2026 the locks were staffed 09:00–18:00 from 26 June to 20 August. Outside the main season there is Friday locking at Skien and Løveid, 09:00–12:00, in 2026 until 2 October. You cannot pre-book, and you pay at the first lock. Fees depend on boat size, so check opening times and fees on the Telemark Canal website before you go.
| Route | Distance | Time | Highlight | Suits |
|---|---|---|---|---|
| Skien–Porsgrunn on the river | approx. 5 nm | approx. 1 h each way | Towns from the water, bridges | Easy day trip |
| Porsgrunn–Brevik | approx. 6 nm | 30–45 min | Brevik old town, Sjøloftet | Lunch trip |
| Island hopping off Brevik | approx. 1–3 nm | half a day | Sandøya, Bjørkøya, swimming | Families |
| Brevik–Langesund and Langøya | approx. 4 nm | 20–30 min | Langøytangen lighthouse, coastal path | Full day |
| Stathelle and Brevik harbour | under 0.5 nm | 1–2 h | Old Stathelle, the harbour | Evening trip |
| Telemark Canal from Skien | approx. 3 nm to Løveid | a day to a week | Locks, Lake Norsjø | Adventure |
Rules and safety in Grenland
- Ship traffic: the Langesundsfjord, Breviksstrømmen and the Frierfjord lead into Grenland's large industrial area. The Norwegian Coastal Administration's traffic centre Brevik VTS (VHF channel 80) monitors the traffic, much of which is gas tankers and other ships with hazardous cargo. The Norwegian Coastal Administration says the most important thing leisure boaters can do is keep a good distance from larger vessels, especially in poor visibility.
- Speed limits: Grenland Havn (the port authority) lists 5 knots in places such as Langesund, Brevik, Sandøysundet and Klokkersundet, 8 knots in Breviksstrømmen and 6 knots on the Skien river. See the full list at Grenland Havn. The BåtFart app shows the limits as you go.
- Bridges: clearance is 45 m under Breviksbrua, 50 m under Grenlandsbrua and 27 m under Menstadbrua. The two bascule bridges in Porsgrunn have 8 m and 13 m and open on request via VHF channel 12.
- Telemark Canal: follow the lock staff, hang fenders on both sides, lead the ropes through your cleats without tying them, switch off the engine in the chamber and wear a life jacket. The waterway is a drinking-water source, so emptying septic tanks or waste is forbidden.
- Licence: Norway requires a boating licence (båtførerbevis) for people born on or after 1 January 1980 who drive a boat over 8 m or with more than 25 hp. Foreign visitors should read our Norwegian boat licence guide to see what applies to them.
Best time for a boat trip in Grenland
Summer is high season. The guest harbours in Langesund and on Langøya run their summer season from 1 April to 30 September, and the Telemark Canal is fully staffed from late June to mid-August. June and August bring long, light evenings. In autumn the river and the Frierfjord are good for calm trips, and Friday locking in Skien continues until the autumn school holiday.
FAQ
Can I take a rented boat into the Telemark Canal?
It depends on the owner, so ask before you book. The locks themselves are open to leisure boats in season. You pay at the first lock, and the fee depends on the size of the boat.
Can a motorboat pass under the bridges in Porsgrunn?
Porsgrunn bridge has 8 m and Frednes bridge 13 m clearance, so most motorboats and RIBs pass without an opening. Sailboats must call the bridge watch on VHF channel 12.
Where can I moor for a meal in Brevik?
Brevik Gjestehavn at Sjøloftet in the inner harbour has 40 guest berths, and Restaurant Sjøloftet is by the pier. In Langesund, the guest harbour is free for up to four hours during the day.
Is the Langesundsfjord safe for a small boat?
Yes, if you keep clear of the shipping lane when large ships pass, follow the speed limits and check the weather before heading out towards Langesund bay. Carry a VHF or phone, and watch the traffic around Breviksstrømmen.
Which island is best for families?
Sandøya and Bjørkøya are close to Brevik and have family-friendly swimming spots and coastal paths. Langøya off Langesund has swimming spots, a 4.5 km loop path and a lighthouse, but is more exposed to the open sea.
Want to continue along the coast? Read Kragerø archipelago by boat to the south or Larvik, Stavern and Sandefjord by boat to the east, and pack with our day-trip packing list.
