Fosen occupies the coastal waters of the Trondheimsfjord and reaches into the open sea beyond. The region's eight sites span wrecks, reefs, kelp forest dives, a cave, and an artificial reef, with something suited to every level from beginner to advanced. Several of the wreck sites, including the M-S Moi and Irma, demand respect for currents and the risk of entanglement, while shallower reef and kelp sites around Hamborra offer more relaxed conditions. The Trondheimsfjord is noted for accessible cold-water coral reefs, and the broader region carries a history of wartime maritime activity.
Monthly water temperature across Fosen's sites, from satellite sea-surface data corrected for depth. The band shows the site-to-site spread.
Water temperatures stay low from late autumn through spring, sitting around six degrees or below, then climb modestly through summer with a peak in September before falling back. Drysuits are standard here throughout the year, and current planning around slack water is important on many of the wreck and reef sites.
7 operators
Water temperature around Fosen ranges from about 6°C in January to 12°C in September, based on satellite sea-temperature data for its dive sites.
In the warm season (about 12°C) a 7mm or semi-dry suit is comfortable in Fosen; in the coldest months (about 6°C) step up to a drysuit.
Fin maps 8 sites in Fosen (8 scuba diving sites).
