Selso was housed in a crate on the ship’s foredeck and secured under cover during the two-day cruise before being released on Saturday off the Port Elizabeth coast, 25 nautical miles out to sea.
Selso spent a month in the transportation crate at uShaka Sea World to prepare him for being on board the ship.
Although those accompanying the seal expected his “ferocious” appetite to be off while he was in the crate, Selso ate his way through 9kg of fish a day. He was hosed down at regular intervals to keep him cool and clean.
When the time came for him to be released, Selso’s crate, with uShaka’s assistant curator of operations, Wayne Sumpton, on the top, was raised over the side of the ship. When Sumpton lifted the gate, Selso, fitted with a satellite tag to track his movements, dived into the water, surfaced briefly and then disappeared.
Originally from the sub-Antarctic region, an underweight Selso was found far from home in June last year.
In August, a team made up of experienced marine biologists decided Selso should be released once he reached a weight of 180kg and had completed his annual moult.
A spokesman for the team, Judy Mann, said although elephant seals are not endangered, the team had been given the chance to save a life and learn more about the species.