MarinescientistFredMillerdesignstheworld'sfirstunderwaterhome,butwhenthebusinessmagnatefundinghisworkthreatenstoendtheproject,Millervolunteerstoliveinitwithhisownfamilytoproveit'spractical.Theunderwaterclanincludeshiswater-phobicwifeandhisdaughterandson,whoarepartofarockandrollband.Theybringalongtheleadsingeranddrummer.Alongtheway,theyhavetocontendwithacompetingengineerwhopromisestominetheoceanfloorforthebusinessman.ArecordproducerlikestheirmusicandbooksthemonTV,leadingthekidstotrytoescapetothesurface.