Fjällbacka, Strömstad and Kosterhavet by boat

Northern Bohuslän is barer, clearer and more exposed than the archipelago further south. By boat you can run from Fjällbacka out to Väderöarna on the edge of the Skagerrak in a day, swim off Hjärterön, or tie up in Grebbestad, where almost all Swedish oysters come from. From Strömstad it is a short hop to the Koster islands and Kosterhavet National Park, and if you like you can carry on across the border to Hvaler in Norway.

Where can you rent a boat near Fjällbacka and Strömstad?

Start from one of the two harbours in this guide: rent a boat in Fjällbacka for the Fjällbacka archipelago, Väderöarna and Grebbestad, or boats for rent in Strömstad, closest to the Koster islands and the Norwegian border. The boats are rented out by private owners, and each owner states what experience or certificate they require. Some owners can also come along as skipper if you would rather enjoy the view than navigate.

6 boat trips around Fjällbacka, Strömstad and Kosterhavet

Distances are approximate, estimated from the chart in nautical miles (M). Always use an up-to-date chart or chart app, especially in the shallow, rocky channels. Two Swedish words you will meet: a gästhamn is a guest harbour with visitor berths, and a naturhamn is a natural harbour, a sheltered cove where you moor to the rocks or anchor.

Fjällbacka to Hjärterön and Dannholmen

Approx. 3 M from Fjällbacka harbour, 2–4 hours with a swim. Hjärterön and Korsön form a nature reserve in the middle of the Fjällbacka archipelago, with coves, rocky and sandy beaches and plenty of sheltered spots to moor. On the east side of Hjärterön stands an old merchant's farm with a herring store from the herring-fishing era, and on Korsö there is a rock formation known as Korsö church. On the way out you pass Dannholmen, the island where Ingrid Bergman had her summer house from 1958. Tip: camping and open fires are banned in the reserve, so pack for a day trip and take your rubbish home.

Fjällbacka to Väderöarna

Approx. 8 M west of Fjällbacka, a full day. Väderöarna (the Weather Islands) is a marine nature reserve of more than 300 islands and skerries at the outer edge of the coast, with kelp forests, eelgrass meadows and one of Sweden's two living coral reefs. On Storö there is a guest harbour for 25–30 boats, a service building with toilets and showers, and Väderöarnas Värdshus, an inn with a restaurant, plus an old pilot lookout you can walk up to. The guest harbour does not take reservations, so arrive early on a summer day. Tip: a 5-knot limit applies around Storö from 15 May to 31 August, and you may not land on islands and skerries that are bird and seal protection areas from 1 March to 31 August.

Fjällbacka to Grebbestad

Approx. 7 M north inside the islands, 2–3 hours with a stop. Grebbestad has a guest harbour and is the heart of Swedish oyster country: around 90 per cent of Sweden's oysters come from Grebbestad and its surroundings, and since May 2023 Grebbestad oysters have EU protected designation of origin. They are harvested from the first week of September until midsummer. To see how it works, book an oyster safari with Bröderna Klemmings Dyk. Tip: go on a guided safari rather than picking your own; picking oysters is expressly banned in Kosterhavet National Park.

Strömstad to Sydkoster and Nordkoster

Approx. 5 M west of Strömstad guest harbour, half or full day. On Sydkoster the guest harbour is at Ekenäs, with restaurants, a hotel and bike rental by the pier, and the national park visitor centre, naturum Kosterhavet, is at Ekenäs pier with free entry. Nordkoster's guest harbours are at Bopallen (Västra bryggan) and Vettnet, with marked trails to beaches and heathland. A car ferry crosses Kostersundet between the two islands in season. Tip: the Kosterbåtarna ferries run between Strömstad and Koster, and a 5-knot limit applies around the Koster islands from 15 May to 31 August, so plan for a slow final stretch.

Around the Koster islands and out to Kosterfjorden

Approx. 15 M around both islands from Ekenäs, 3–4 hours. Beneath you lies Kosterrännan, a deep trench with steep rock walls and living cold-water coral reefs that make Kosterhavet unique in Sweden. The national park covers almost 400 square kilometres, nearly all of it sea. Out among the skerries there are bird and seal protection areas, so follow the chart and the yellow signs. Tip: if you want to swim off a sandy beach, anchor at least 50 metres out between 15 May and 31 August, and some coral and seabed areas are completely closed to anchoring.

Koster to Ytre Hvaler in Norway

Approx. 8–10 M from Vettnet on Nordkoster to Skjærhalden on Hvaler, a full day. Kosterhavet National Park borders the Norwegian Ytre Hvaler National Park, and the two parks were opened on the same day, 9 September 2009, together protecting the sea on both sides of the border. The Norwegian side has its own rules, including a landing ban at seabird sites from 15 April to 15 July. Our guide to Hvaler by boat covers the Norwegian side in detail. Tip: ask the owner in advance whether the boat may be taken across the border, and check the customs rules for anything you bring back.

The trips at a glance

Rules and safety in Kosterhavet and Fjällbacka

Kosterhavet National Park is managed by the County Administrative Board of Västra Götaland (Länsstyrelsen), and its regulations apply across the whole park. Read them on Länsstyrelsen's Kosterhavet page and at kosterhavet.se, which also has a map of all the zones.

• Speed: max 25 knots throughout the national park and max 5 knots around the Koster islands from 15 May to 31 August. The same 5-knot limit applies around Storö in Väderöarna from 15 May to 31 August.
• Anchoring: you may not moor or anchor in the same place for more than two days in a row. From 15 May to 31 August you may not pull up or moor a boat on a sandy beach, or anchor closer than 50 metres to one. Canoes and kayaks may be pulled up if they do not block the beach.
• No-anchoring zones for corals and seabed: anchoring is banned in zone D, which includes Säcken, Hällsöflaket, Grisbådarna, Kungsviksflaket, Björns rev, Ullvillarna and Spiran. In Väderöarna anchoring is banned in areas including Sollidbukten.
• Birds and seals: in the park's bird protection areas (F) and bird and seal protection areas (FS) you may not stay or travel from 1 March to 31 August, at Mörholmen from 1 March to 15 July, and in seal protection areas (S) from 15 May to 15 July. In Väderöarna you may not land and must keep 100 metres away from 1 March to 31 August.
• Other park rules: jet skis are banned in zone C, in zone E motorboats may only go to and from a mooring point, idling engines and drones are banned, and picking oysters is forbidden.
• Koster ashore: overnight stays on land on Nordkoster and Sydkoster are banned except at the designated campsite.
• Right of public access on the water: under allemansrätten you may anchor and moor temporarily by a shore that is not part of someone's garden, and sleep aboard for a night or so. Jetties that belong to a house are private. More at Naturvårdsverket.
• Toilet waste: discharging toilet waste from leisure boats is banned in Swedish waters. Empty the tank in harbour.
• Traffic: the Kosterbåtarna ferries run between Strömstad and Koster, and a car ferry crosses Kostersundet. Keep clear and keep a lookout in the sound.

Licence: in Sweden no boating licence is needed for a leisure boat that is under 12 metres long or under 4 metres wide, whatever the engine. Only a boat at least 12 metres long and at least 4 metres wide requires a kustskepparintyg (coastal skipper certificate) or higher, and this applies to visitors too. See our guide to boat licence rules in Sweden. The drink-driving limit at sea is 0.2 per mille on boats that can do at least 15 knots or are at least 10 metres long.

Best time for a boat trip in Kosterhavet

High season is June to August, when harbours are best staffed: the Väderöarna harbour master is on site from 1 June to 31 August. Strömstad guest harbour and the Väderöarna guest harbour are open all year. Several rules follow the season: the 5-knot limit and the 50-metre beach rule apply from 15 May to 31 August, and bird protection from 1 March to 31 August. May, early June and September bring quieter harbours. September also opens the oyster season in Grebbestad, and Oyster Day is held there every September.

FAQ

Can you anchor anywhere in Kosterhavet National Park?

No. Anchoring is banned in zone D around coral reefs and sensitive seabed, from 15 May to 31 August you must stay at least 50 metres off sandy beaches, and you may not stay in the same place for more than two days in a row. Check the zone map on kosterhavet.se before you drop anchor.

How long does it take by boat from Strömstad to Koster?

It is approx. 5 M to Ekenäs on Sydkoster or Vettnet on Nordkoster. A fast motorboat does not need long, but expect 5 knots for the last stretch around the islands in summer. The Kosterbåtarna ferry takes about 45 minutes.

Can I book a guest berth on Väderöarna?

No, the guest harbour on Storö does not take reservations and has room for 25–30 boats. In Strömstad, however, you can book a guest berth in advance through the municipality's harbour website, which is recommended in the peak summer weeks.

Can I pick my own oysters near Grebbestad?

Picking oysters is forbidden in Kosterhavet National Park. The easiest way to taste Grebbestad oysters is a guided oyster safari or a restaurant in the harbour; the season runs from September to midsummer.

Is Kosterhavet suitable for an inexperienced skipper?

The trip from Strömstad to Koster is short and follows a well-marked channel, so it suits many. Väderöarna and the run to Hvaler are more exposed to the Skagerrak and best left for a calm day and an experienced hand. If you are unsure, choose an owner who comes along as skipper.

Heading south? Read our guide to Smögen and Sotenäs by boat and our overview of the best places in Bohuslän by boat.