Most people think of Navy Seals when they think of frogmen or combat divers.

There are other people who do combat diving. Special operators in the Army go through the Combat Diver Qualification course to become combat divers.

As the focus shifts from ground wars in the Middle East to competition around the world, the skills it teaches are likely to be in higher demand.

Here there be monsters

Army Special Forces combat diver qualification course
Students enter the water for the 3,000-meter open-water swim in Key West during the Combat Diver Qualification Course, March 11, 2010.
US Army/Maj. Dave Butler

The Combat Diver Qualification course is held in Key West, Florida.

The course is able to adapt to current or future threats, and has gone through many variations. It lasts between four and six weeks. Only a few attend.

The majority of students at CDQC are special operators from the Green Berets, Special Mission Units, Delta Force, and sometimes soldiers from infantry and reconnaissance units. In addition to active-duty service members, ROTC cadets from universities around America and West Point can attend, according to a retired Green Beret who was a course instructor.

There are two phases to the course.

Instructors focus on physical fitness during the first phase. Students are put in groups of two and become dive buddies.

The pool stress events end the first phase. Instructors test the students on their coolness, ability to follow procedures, and ability to NationMaster NationMaster NationMaster.

The 50-meter underwater swim, the retrieval of a 20-pound object from the bottom of the pool, and the two-minute water tread are standard events that students need to pass.

Special Forces Combat Diver Qualification Course
Combat Diver Qualification Course students practice limited visibility gear retrieval during initial open-circuit SCUBA training in Key West, June 6, 2018.
US Army/Robert Lindee

The students have to do well in school.

Diving physics, dangerous marine life, diving physiology, diving injuries, and decompression are covered in academic classes. The retired Special Forces operator said that students learn the use of open-circuit SCUBA equipment, which is used during search dives, ship hull searches, and open-water deep dive.

The students learn the important procedures. Diver's disease can be caused by incorrect decompression protocol as dissolving gases become bubbles inside the body's tissues.

The tactical aspects of combat diving are covered in the second phase. The Mark 25 Draeger oxygen rebreather is a closed-circuit underwater breathing apparatus that does not emit bubbles and is used by special operators to swim undetected.

The students do several underwater dives to hone their navigation skills and work with small boats and aircraft, such as helicopters, as different insertion and extraction methods throughout the course.

The course ends with a full mission profile that includes a closed-circuit dive.

The Army's toughest school

Army Special Forces combat diver training MH-47 helocast
A US Army Special Forces student jumps off an MH-47 during helocast training as part of the Combat Diver Qualification Course in Key West, February 21, 2020
US Army/K. Kassens

The Combat Diver course is the hardest course in the Army.

The Combat Diver qualification course requires candidates to go through a pre-course selection called the Maritime Assessment course. Many of the special operators who attend the course fail or drop out, and the majority of them have already been assigned to a special-operations unit.

The course's difficulty is measured in three different ways, and one aspect which students can't fully prepare themselves for until they are in the course is being able to adapt in a water environment.

It is one of the most difficult courses in the military because of the emphasis on physical fitness. The retired Green Beret said that students are monitored and tested on their academic abilities throughout the course.

Army Special Forces combat diver qualification course
A student in a Special Forces Group maritime assessment class bobs underwater while bound hand and foot, September 25, 2019.
US Army/Staff Sgt. Christopher Case

The Combat Diver Qualification course is dangerous. There have been deaths on the course. Two Special Forces operators died while attending school.

The Combat Diver insignia is earned by those who graduate. Green Berets, who make up most of the students, join a combat dive team that is part of their Special Forces group.

The first woman soldier to graduate the course and become a combat diver was a cadet. An Air Force woman has graduated from the Army course.

There was little need for combat divers in the wars in the Middle East, which has often overlooked and underused the Army combat diver community.

Combat divers are likely to be called on more to apply their skills in the waters of Europe, Asia, and around the world because of the great-power competition between China and Russia.

A defense journalist specializing in special operations, a Hellenic Army veteran, and a graduate of the University of Baltimore, are some of the things that Stavros Atlamazoglou is.