Two Otago Boys' High School pupils sustained serious injuries when the support vessel hit an eight-man rowing skiff on October 19, 2014.
The incident occurred when veteran rowing coach Fred Strachan (92) slipped inside the boat, which went "at speed" towards the novice crew, forcing them to jump or be thrown off.
One boy had his arm badly injured by the support boat's propeller and the other suffered a head injury.
The incident summary and photos of the damaged skiff emerged after Maritime New Zealand released a heavily redacted 323-page report under the Official Information Act, Fairfax reports.
"The potential for death was very real, and in this case very close. Serious injuries were sustained by multiple children," the report says.
A draft summary of facts shows the school's board was initially facing two charges under the Maritime Transport Act, each with a maximum fine of $100,000.
Maritime New Zealand later dropped a charge for operating a ship without the appropriate document.
In December 2015, Maritime NZ issued a statement saying charges against the school and the coach had been dropped.
The school's lawyers successfully argued that the school, as a Crown organisation, could not be charged under the Maritime Act.
Both the school and Strachan accepted full responsibility for the crash. The school paid compensation to the injured boys, while Strachan retired from coaching rowing.
