The leaders of the expedition were reluctant to call their commanding officer to seek permission to change the day's training plan, so they decided to have Harris and Reyher use scuba gear and estimated that a single canister of air would be enough for the two to complete the task.
The investigation, which called the leaders' actions 'multiple points of failure and decision making' found that the limited air did not allow for the divers to deal with any unforeseen difficulties.
Harris and Reher were among their unit's most experienced divers, but the men faced a series of difficulties with their equipment, communication with the surface was patchy and finally, Debris beneath the murky water trapped Reyher 150 feet underwater.
Harris and Reyher were connected to each other and the boat. Harris could have cut the cord connecting him to Reyher and swim free, but he didn't.
'Harris exhausted himself in an attempt to save Reyher,' the investigator concluded.
'Both divers resisted the natural instincts of self-preservation, in order to expel his last breaths in an effort to save each other.'
Harris will posthumously receive the Navy and Marine Corps Medal for his actions.
The award is typically given to members of the Navy and Marine Corps who demonstate heroism during non-combat situations.
Harris was married to his high school sweetheart, Deanna Favoroso Harris, and the pair had two young daughters.
Reyher was also married, to Diana Kafury Reyher, whom he 'loved to spoil and aggravate,' according to his obituary.