A tourist captured an unknown hero's dramatic rescue of the man found floating unconscious in Hamilton Harbour last Saturday.

Amateur photographer Chink Pope was walking through Hamilton when she spotted the 46-year-old Devonshire man in the water off Albouy's Point.

The woman snagged a few snapshots of the man, who was lying in an unresponsive state, before he was brought to safety by an unknown passerby who jumped into the water and brought him to the Ferry Terminal dock.

According to Police reports, officers including members of the Marine Police Unit, arrived on the scene at approximately 2.30 p.m. when they were able to help manoeuvre the still unconscious victim out of the water using a life buoy. Ms Pope remained to take pictures of those efforts, also capturing shots as an officer performed CPR on the victim until the arrival of paramedics.

Police are investigating but say it appears a pre-existing medical condition may have resulted in the man falling overboard, as he had no apparent injuries.