MarinescientistFredMillerdesignstheworld'sfirstunderwaterhomebutwhenthebusinessmagnatefundinghisworkthreatenstoendtheprojectMillervolunteerstoliveinitwithhisownfamilytoproveit'spracticalTheunderwaterclanincludeshiswaterphobicwifeandhisdaughterandsonwhoarepartofarockandrollbandTheybringalongtheleadsingeranddrummerAlongthewaytheyhavetocontendwithacompetingengineerwhopromisestominetheoceanfloorforthebusinessmanArecordproducerlikestheirmusicandbooksthemonTVleadingthekidstotrytoescapetothesurface