Busteinsundet is a wall dive located in Hvaler and Fredrikstad, Norway. The site features a vertical rock face that drops from 15 metres to a depth of 25 metres. Divers should expect visibility between 5 and 10 metres and water temperatures ranging from 4C to 14C, making a drysuit necessary. Access to this site requires a boat. While the wall offers a stable environment for exploration, divers must remain aware of strong currents and monitor conditions throughout the dive. Night diving is possible, allowing for observation of invertebrates that become more active after dark. This site is suitable for intermediate divers.

Ferder Fyr is a reef and wall dive site located in the waters of Hvaler and Fredrikstad. The site features depths ranging from 18 to 30 metres, though it extends to 50 metres, requiring careful depth monitoring to manage nitrogen narcosis risks. Divers experience visibility between 5 and 10 metres with mild currents. Due to water temperatures fluctuating between 4 and 14 degrees Celsius, a drysuit is strongly recommended to prevent hypothermia. Access is by boat only, and the site is suitable for beginners with appropriate certification. Hazards include cold water, entanglement, and potential surf conditions. Always confirm local boat logistics and current conditions before planning a dive.

Skarvesetet in Hvaler and Fredrikstad offers a combination of a drop-off and a gentle drift, providing a practical introduction to cold-water diving in Southern Norway. The site features depths ranging from 18 to 26 metres, with an average depth of 11 metres. Visibility is variable, typically spanning 10 to 30 metres. Due to water temperatures between 4 and 15 degrees Celsius, a drysuit is essential for comfort. Access is exclusively by boat, and the mild currents make this site suitable for beginners. Divers should remain aware of potential entanglement risks and manage gas consumption carefully given the depth and potential for surge.

Svenner fyr is a reef dive located off the coast of Hvaler and Fredrikstad, Norway. The site features a reef structure extending from 10 to 30 metres in depth, making it suitable for beginners. Divers experience mild currents and visibility ranging from 5 to 10 metres. Due to water temperatures between 5 and 13 degrees Celsius, a drysuit or thick wetsuit is essential. The reef supports various temperate marine life and invertebrates. Access is by boat only, and divers should remain aware of boat traffic during ascents. Use caution near the reef, as the rocks are sharp.

Missingene in Hvaler and Fredrikstad offers a diverse underwater environment featuring both a wreck and a reef. Divers can explore depths ranging from 5 to 30 metres. The site is accessible only by boat and is suitable for beginners, with currents typically remaining mild. Visibility at the site generally ranges between 5 and 10 metres. Water temperatures are cold, fluctuating between 4C and 14C throughout the year. On-site facilities include toilets for visitor use. Due to the cold water conditions, appropriate thermal protection is required for all dives.

Kostersten is a reef system located in the cold waters of the North Sea near Smögen. The site features a topography that drops from 22 to 45 metres, with an average depth of 30 metres. The reef is characterised by kelp forests and bordering seagrass beds. Access is by boat only. Conditions include mild currents and visibility ranging from 10 to 30 metres. Due to the cold water temperatures between 4 and 13 degrees Celsius and the significant depth, this site is suited for intermediate divers. Divers must use a drysuit and manage gas consumption carefully to mitigate risks associated with nitrogen narcosis and deep diving.

Svarteberget is a reef site in southern Norway characterised by a rapid drop-off into deep water. Divers typically explore depths between 20 and 50 metres, with an average depth of 35 metres. The site features mild currents and visibility ranging from 5 to 10 metres. Due to the cold water temperatures, which fluctuate between 4 and 13 degrees Celsius, a drysuit is essential. Access is by boat only. Divers should remain vigilant regarding boat traffic at the surface and potential entanglement hazards within the reef structure. Species recorded around this area include the orange-clubbed nudibranch, grey sea slug, and various snails.

Bleksund is a boat-access reef located off the coast of Smögen, Sweden. The site features a rocky reef topography with depths ranging from 16 to 35 metres. Divers can expect mild currents and visibility typically between 10 and 30 metres. Due to water temperatures ranging from 4 to 14 degrees Celsius, a drysuit is recommended for all dives. While the site is manageable for beginners working on buoyancy, the depth requires careful planning and adherence to certified depth limits. Cold water conditions are a primary hazard, necessitating conservative bottom times even during the warmer summer months.