during "voyager's" journey to earth, a large number of shuttles were lost, eventually requiring a new spacecraft. the "delta flyer" was introduced in the episode "". equipped with warp drive and technological enhancements gleaned from the borg, the "delta flyer" was far more capable than the standard shuttles it replaced. like the aquashuttle in "the animated series", the "delta flyer" could submerge and travel in water.