Matterhorn is a freshwater reef dive located in Lake Thun, Switzerland. The site features a reef structure extending from the surface to a maximum depth of 30 metres. Divers can expect visibility between 5 and 15 metres. Due to moderate currents, this site is suitable for divers with at least an Open Water certification. Cold water is a significant hazard, requiring the use of a drysuit or a thick thermal exposure suit. Facilities on site include a dive shop, air fills, equipment rental, and guided tours. Species recorded around this area include snail, common perch, burbot, barbel, chub, pike, American crayfish, and bullhead.

Ameisenecke in Lake Thun features a distinctive wall and reef topography that drops rapidly from the shore. Divers can navigate a horseshoe-shaped route at depths between 22 and 25 metres, with the site reaching a maximum depth of 25 metres. This alpine freshwater location offers visibility ranging from 5 to 15 metres and mild currents. Due to the cold water temperatures, which fluctuate between 10°C in winter and 18°C in summer, proper thermal protection and buoyancy control are essential. The site is accessible from the shore, with limited parking available nearby. Species recorded around this area include snail, common perch, burbot, barbel, pike, chub, bullhead, and American crayfish.

Stampach in Lake Thun is a demanding freshwater dive site featuring a wall and canyon topography. The site reaches depths of 34 metres, with an average depth of 22 metres. Divers enter from the shore, located 50 metres from the main structures. The environment is characterised by strong currents that can funnel unpredictably through the canyon, requiring careful planning and advanced buoyancy control. Visibility typically ranges between 6 and 10 metres. Due to the significant depth, potential for entanglement, and overhead environments, this site is suited for advanced divers. Facilities at the shore entry point include parking and a rinse station.

Niesen in Lake Thun offers diverse freshwater diving across reef, wall, and muck environments. The site extends from 7 to 46 metres, with deeper sections requiring decompression procedures. Divers should expect mild currents and visibility ranging between 6 and 10 metres. Due to the significant depth and cold water temperatures, which fluctuate between 4 and 24 degrees Celsius depending on the season, this site is suited for intermediate divers with appropriate thermal protection. Shore access is available with parking located at the entry point. Divers should maintain strict awareness of their dive profile and depth throughout the typical 35-minute dive.

Bäregg in Lake Thun offers a distinct freshwater diving experience characterised by underwater rock formations and small vertical walls. The site reaches depths between 20 and 30 metres, with an average depth of 25 metres. Divers enter from the shore for a typical 50-minute dive. Visibility at this site ranges from 5 to 10 metres. Species recorded around this area include snails, common perch, burbot, American crayfish, barbel, bullhead, chub, and pike. Due to the presence of boat traffic, cold water, and variable visibility, this site is best suited for intermediate divers. Parking and toilets are available at the location.

Längenschachen in Lake Thun offers a gentle, sloping dive profile suitable for beginners. The underwater terrain transitions from stony to muddy, with seagrass beds extending to a depth of 5 metres. Divers typically reach depths between 2 and 15 metres, with an average of 10 metres. Access is via an easy shore entry located 50 metres from the parking area. Conditions feature mild currents and visibility ranging from 3 to 10 metres. The site is also popular with bathers during summer months, requiring awareness of boat traffic and surface activity. Facilities at the site include parking, a cafe, and toilets. Night diving is permitted at this location.

Spiezerberg is a deep freshwater wall and canyon dive located in Lake Thun. The site features topography ranging from 20 to 40 metres, with an average depth of 30 metres. Access is by boat only, and divers should be prepared for cold water temperatures, which remain constant at 5-6°C below the thermocline. Visibility typically ranges between 5 and 10 metres. Due to the significant depth and potential for entanglement on sharp rocks, this site is suited for intermediate divers. Facilities including air fills, showers, and changing rooms are available nearby. Species recorded around this area include snail, common perch, burbot, barbel, American crayfish, chub, pike, rainbow trout, and bullhead.

Spiez Wallrain is a freshwater site located directly below Spiez Castle in Lake Thun. This reef and artificial reef site features a pebble-bottomed bay, providing an accessible environment for snorkelers. Entry is facilitated by secured steps leading directly into the water. The site offers depths ranging from 2 to 15 metres, with an average depth of 8 metres. Visibility at this location typically varies between 6 and 10 metres. The site is suitable for beginners and includes toilet facilities for visitors. A typical session lasts approximately 45 minutes.