The 12072 gt oil rig GSF Arctic 1 suffered water ingress while in Guanabara Bay near Rio de Janeiro, Brazil.  The oil rig suffered water ingress into one of the legs when the crew was performing maintenance.  The rig began to list several degrees requiring some of the crew to be evacuated.  The crew later returned to the rig after the water was pumped out.   No reports of injuries, damage or pollution being released.   An investigation is being conducted into the cause of the incident.