Kosterhavet and Stromstad

Preparation and Risk Management

• Choose dives within recent certification, cold-water experience, gas and decompression limits. An old operator page or empty calendar is not proof a guide or boat is running.
• Confirm the actual site and current local currents, wave exposure, visibility, temperature profile, entry/exit, ferry and vessel routes, and required signalling.
• Agree buddy and surface-support roles, recovery route, communications, emergency oxygen and evacuation procedure before entering. Use a DSMB and other locally required markers.
• Freediving depth training needs dedicated trained safety supervision and should not be inferred from the two shallow snorkeling trails.
• Stop if conditions, thermal protection or medical fitness do not match the plan. Local club information; Park snorkeling precautions.

Legally Excluded Zones

The county introduced diving prohibitions effective December 19, 2025, over six specified cold-water coral restoration areas: Sacken, Grisbardarna, Bjorns rev and Ullvillarna in Stromstad municipality, plus Spiran and Djuprannan in Tanum municipality. These are legal area prohibitions associated with deep coral habitat, not merely an advisory to avoid going past a particular depth at an otherwise prohibited coordinate. The county says established recreational sites were excluded by redrawing the zones. Request the current legal map and confirm your exact coordinates, rather than treating reef names or brochures as a dive invitation. County announcement; Binding Stromstad rules; Binding Tanum rules.

Call 112 for suspected decompression illness, serious breathing problems, loss of consciousness, water rescue or other emergencies. If afloat, use VHF channel 16 and call sign SWEDEN RESCUE where the vessel is equipped to do so. Inform the dispatcher that a dive or breath-hold incident occurred; follow emergency response instructions. Swedish maritime rescue.

For non-emergency advice, Sweden's 1177 health service provides guidance, and Capio Stromstad is listed for local primary care; this is not a hyperbaric chamber or guaranteed emergency service. The Sahlgrenska University Hospital hyperbaric unit is in Gothenburg, so evacuation and specialized care should be coordinated by emergency services. Do not promise a particular evacuation time, chamber availability or ability to continue diving. 1177 advice; Local primary care; Hospital specialist unit.

Before departure, verify insurance for recreational or specialist diving, cold-water exposure, ambulance or maritime rescue, recompression treatment and travel interruption. Emergency oxygen and a documented rescue plan should be checked with the actual trip provider.

Kosterhavet is Sweden's first marine national park and contains sensitive seagrass, kelp and cold-water coral habitat. Follow the park and adjacent island nature reserve rules separately. Do not disturb or collect oysters, marine life, plants, rocks or seabed features. Avoid bottom contact, damaging anchors and fishing in relevant seabed-protection zones. Publicly accessible marine scenery does not equal unrestricted dive access. County park rules; Islands reserve.

Seasonal protected-zone buffers: bird sanctuaries generally have a 100 m exclusion from March 1-August 31 (with a shorter to-July-15 period at Morholmen); seal protection areas have a 100 m exclusion May 15-July 15. Rules also restrict boats within 50 m of certain beaches during May 15-August 31, seasonal speed limits in designated areas, drone use and anchoring in protected seabed zones. Consult authoritative maps for the actual polygons, exceptions and legal definitions. Primary rules.

An authorized seal-looking boat trip is not consent to enter a sanctuary, land on a forbidden island or chase a marine mammal. No wildlife encounter is guaranteed. Official tourism options.