Heather Island offers a diverse underwater experience within the Sound of Mull, featuring a wall, a cave system, and a wreck in one location. Suitable for beginner divers, the site provides a variety of topography without significant currents. Depths range from 15 to 30 metres, with an average of 20 metres. Visibility typically varies between 5 and 10 metres. Due to water temperatures ranging from 8 to 14 degrees Celsius, a drysuit or a minimum 7mm wetsuit with hood and gloves is strongly recommended. Boat access is required for this site, and local facilities provide air fills, equipment rental, and boat charters.

Ganavan Sands in Oban offers an accessible shore entry via a concrete ramp, leading into a bay characterised by a mix of sandy bottom, rocky outcrops, and seagrass beds. This site is suitable for beginners, with depths ranging from 1 to 8 metres and an average depth of 4 metres. Snorkellers can explore the kelp forest and seagrass habitats, which support a variety of regional marine life and invertebrates. Conditions are variable with mild currents and visibility typically between 5 and 10 metres. Water temperatures are cold, ranging from 4°C to 14°C. Hazards include boat traffic, cold water, entanglement, jellyfish, and low visibility.

SAMS Beach is a horseshoe bay located in the Sound of Mull, sheltered by rock formations. This site offers shore access for snorkelers, with depths ranging from 2 to 15 metres and an average depth of 7 metres. The underwater topography consists of reefs and kelp forests. Conditions are generally mild, making this a suitable location for beginners. Facilities available at the site include parking, a cafe, and showers. The site is situated next to the Scottish Association for Marine Science.

The SS Breda is a Dutch freighter from the Second World War located in the Sound of Mull. The wreck sits upright on the seabed at depths ranging from 12 to 35 metres, with an average depth of 18 metres. Access to the site is by boat only, situated 2400 metres from the shore. Divers may encounter a halocline and thermocline, creating a noticeable difference in water colour and salinity between the surface and deeper sections. The site is suitable for intermediate divers and offers an overhead environment. Snorkellers can explore the upper decks, though the deeper sections are restricted to scuba divers.

The Thesis Wreck is a notable shipwreck located in the Sound of Mull, resting at depths between 20 and 32 metres with an average depth of 26 metres. This site is suited for intermediate divers due to the strong currents and the requirement for precise slack water timing. The wreck structure offers penetration and swim-through opportunities, though divers must remain cautious of entanglement hazards. Visibility typically ranges from 5 to 10 metres. Water temperatures vary from 8 to 14 degrees Celsius, making a drysuit essential. Access is by boat only, and divers should carry a surface marker buoy and a cutting tool. Active boat traffic is common in the area.

Asknish Bay offers a sheltered environment for snorkelling, featuring rocky reefs and kelp forests. The site is suitable for beginners, with depths ranging from 2 to 15 metres and an average depth of 7 metres. Entry is accessible via the jetty steps or the boathouse path. Conditions are generally mild, though snorkellers should remain aware of boat traffic in the area. Facilities available at the site include parking, toilets, and a cafe, with guided tours also offered. The bay provides views of Shuna and Luing, and the location is suitable for night snorkelling.

Bonawe Quarry is a shore-accessible dive site located in a natural harbour featuring manmade structures. The site is known for the wreck of the Fore Derrick, a small fishing boat resting in approximately 14 to 15 metres of water. Divers can access the site via a slipway, following a mooring line from 5 metres depth to reach the vessel. The wreck offers the opportunity to explore the wheelhouse, though precise buoyancy control is required to prevent silt out. Conditions at this site are variable with mild currents and cold water temperatures. Due to the presence of wreckage and potential for entanglement, this site is suited for intermediate divers.

Creagan is a high-energy marine site located on the north shore of Loch Creran near the Creagan Inn. The topography consists of a mix of reef and artificial reef structures, offering diverse seabed types. Divers can expect depths ranging from 3 to 25 metres, with an average depth of 14 metres. Access is via the shore, though the site is subject to strong currents and boat traffic. Due to these conditions, the site is suited for intermediate divers. Visibility at the site typically ranges between 3 and 10 metres. Facilities available at the location include parking, showers, and a cafe.