Many divers know this classic ship from her previous life as the Undersea Hunter of Cocos Island and IMAX fame. With massive upgrades including stretching by 20 feet, a new superstructure, an enclosed dive deck and host of other improvements, it is hard to recognize the original ship. The special feature of the Under Sea is intimate group size of just 18 divers combined with Nautilus spaciousness and comfort and a huge dive deck and water level platform. It is important to note that the ship was launched in 1968 and she is not as new and contemporary as the other Nautilus Fleet Liveaboards.