Hi ultramarina ~ My kiddos are still fascinated with the underwater world. Two shows my kids love are MonsterQuest and the Underwater Universe. If you go on the History Channel website, there are videos to watch and interactive sites under MonsterQuest to learn all about the giant squid, Nessie, eels, giant octopus etc...A great DVD is DK Eyewitness Ocean. My kids at age 4 loved all of this and made them even more passionate, but some of this might be a little too intense for other kids...( I don't know??), so I would probably check it out first
