BY NBC6.net,

Authorities are investigating the death of a man who was diving near Key West aboard a National Oceanic and Atmospheric Administration vessel.

The Monroe County Sheriff's Office says the 54-year-old from Ramrod Key and a buddy were surveying the sea floor on Monday for an upcoming coral restoration project. They were heading back to the surface -- from 80 to 100 feet under -- and reached a decompression stop when the buddy noticed the man floating downward.

Authorities say other divers went into the water and retrieved the man. They performed CPR and called the Coast Guard. A helicopter took the man to Lower Keys Hospital, where he was pronounced dead.

The man's name has not been released pending notification of his family. An autopsy has been scheduled

----------------------------------------------------------------------