He wasn't the owner of the boat that he was found on.
Borrell says forensic scientists were onsite, as well as those doing luminal testing and finger print testing.
"We are examining three boats moored in the area gathering any evidence that will assist this investigation to piece together what has actually occurred and has led to this man's death. It is expected that this will take several days."
The boats are located opposite Neale Park playing fields.
Police say anyone who saw people in the area on Wednesday afternoon or Thursday morning can call 03 546 3895 or Crimestoppers on 0800 555 111.