Army engineer divers are members of national armies who are trained to undertake tasks underwater, including reconnaissance, demolition, and salvage. These divers have similar skills and qualifications as professional divers. Army divers use both surface supplied "Hard hat" and SCUBA to perform their missions. In the United States Army, they are members of the Corps of Engineers. In the British Army, they may be Royal Engineer Divers or Commando Engineer Divers.

Army engineer divers are members of national armies. Army engineer divers are trained in underwater construction, salvage, demolitions, hydrographic survey, hyperbaric chamber operation, beach and river recon, bridge recon, underwater cutting and welding, side scan sonar operations, mine and countermine operations, and search and recovery operations. They are also training in ships husbandry operations. These divers have similar skills and qualifications as professional divers.

The earthquake of January 12, 2010, that left thousands of Haitians dead or homeless and hungry, rocked Haiti's main port of Port-au-Prince. Shockwaves sent the port's busy northern pier and its two massive cargo cranes sinking into the sea. The harbor was littered with toppled shipping containers. The southern pier was sheared from its concrete support pilings. The U.S. military worked with Haitian authorities to offload seaborne humanitarian aid and commercial cargo as it helped run the port. At the heart of its plans was an effort to repair the remains of the southern pier, leaving Haiti with a vital avenue for humanitarian aid and commerce.

Depending on situation they may use: Diving helmets used for surface-supplied diving, or Full-face diving masks used with surface supplied and scuba equipment or Scuba diving equipment is generally used for dives requiring high mobility.

Diving medical personnel evaluate the fitness of divers before operations begin and are prepared to handle any emergencies which might arise. They also observe the condition of other support personnel and are alert for signs of fatigue, overexposure, and heat exhaustion.

In the United States Army, engineer divers are members of the Corps of Engineers. In the British Army, they may be Royal Engineer Divers or Commando Engineer Divers.

In the British Army, the Corps of Royal Engineers has a specialist role of Royal Engineer Diver dating back to 1838 under Colonel Charles William Pasley. They are trained at Horsea Island alongside Royal Navy divers for the tasks required of an engineer diver, such as underwater thermic lance cutting, concreting and demolition. In addition, the reserve Commando Engineer Divers of 131 Commando Squadron Royal Engineers, a part of the 24 Commando Engineer Regiment Dive Team, are trained as divers to the same standards.

Deep sea divers have been a part of the United States Army since the Spanish–American War. In 1898, they constructed a cofferdam around the USS Maine (ACR-1) to facilitate the ship's inspection and determine the cause of its sinking. Later, during World War I, Army divers built and inspected bridges, tunnels, and port facilities.