Rocky is working as a lifeguard at Angel Grove Lake. One of the young kids he's watching over, named Dougie, is afraid of going out for a swim, thinking monsters inhabit the waters. Lord Zedd, you guessed it, is inspired, and recreates some of his (and Rita's) more sinister water-based monsters. Slippery Shark, Piranhtishead, Toxic Goo-fish, and Commander Crayfish are reborn to wreak havoc. Billy & Aisha help Rocky out against the school of baddies, but the other three Ranger Teens are currently out scuba-diving! Even if the Rangers manage to defeat these monsters again, can they stop Zedd's newest creation, Tube Monster, the white & blue stripped innertube-based monstrosity? And can Dougie overcome his fears to save Bulk & Skull's lives?