Police call in navy's undersea robot to find drowned man

The Remote Environmental Monitoring UnitS (Remus), operated by the navy. Photo / Supplied

The body of a man who went missing off an Auckland beach last week would never have been found if it were not for an underwater navy "robot".

Mark Thomas, 52, was last seen paddle-boarding off Takapuna Beach last Wednesday. Police found his board later that day and started a search.

"We engaged the navy and in particular the navy mine countermeasures team on Friday, and with their help and the maritime police we were able to search a large area of the water off Takapuna Beach," said Detective Sergeant James Watson.

"Using information from the Remus, a figure which was 1.8m long was discovered about 500m off Thorne Bay."

The Remus is a seabed vehicle that can accurately search large underwater areas for up to eight hours at a time.

The Remus had to be pulled out after two hours of a planned four-hour search because of worsening weather.

Luckily it had already captured the image police needed.

As they downloaded the material filmed underwater, police were able to identify Mr Thomas clearly.

Divers battled rough seas, pitch black water and 30cm of visibility to bring Mr Thomas back to his family.

It is presumed he drowned and the matter has been referred to the coroner.

"Without doubt if the navy's resources were not deployed as soon as they were, the body would not have been discovered," Mr Watson said.

"This joint defence and police operation showed an effective and efficient use of the government's resources available to obtain a positive result. In this case it was to return the body to the family to provide some closure."

THE REMUS
* Remote Environmental Monitoring Unit for conducting seabed searches.
* Can record black and white video for object identification.
* Can accurately search large areas of seabed quickly.
* Programmed onshore with the mission search grid and settings.
* Once a mission is completed, data from the Remus is downloaded and analysed.