Sweeper Cove serves as the main harbour area of Adak, featuring industrial remnants that function as artificial reef structures. This site is suited for advanced divers due to the cold water temperatures ranging from 3C to 6C and moderate currents. Depths at the site vary between 11 and 40 metres. Access is available via both shore and boat entry. Divers and snorkellers should remain aware of boat traffic in the area. The habitat supports a variety of temperate marine life, including various fish and invertebrates typical of the region. Due to the challenging conditions and cold water, proper thermal protection is essential for all activities.

Finger Bay is a deeply recessed, protected bay located on Adak Island. It offers relatively stable conditions for both diving and snorkelling in the central Aleutians. Divers and snorkellers can access the site from the shore or by boat. Water temperatures are cold, ranging from 4C to 9C throughout the year. Due to the environment, divers should be prepared for cold water, potential entanglement hazards, and variable visibility. The site features parking facilities for visitors. It is recommended for advanced divers due to the challenging water temperatures and environmental conditions.