Barnacles Bear is the captain of the Octonauts and one of the bravest polar bears you will ever meet. Always the first to rush in and help when there's a problem, the crew has great respect for him.
Along with being the captain, Barnacles is also the strongest member of the crew and he's demonstrated that in a number of different episodes. He's also one of the most level-headed crew members, often dismissing his crew mate Kwazii's outlandish stories about sea monsters and ghosts.
It's also been revealed that he rather fancies playing the accordion. To his mind, he's quite good at it, but Kwazii, who has the misfortune of living in the same pod, doubts it, as seen in "Octonauts and the Orcas". So far the only ones to appreciate the music have been a pod of Orcas.
In both UK and US version Captain Barnacles has the same accent.