This book by Victor Appleton is another one I picked up recently at the old Dawn Treader, but it’s one that I’ve already read. I was probably in middle school or something like that when I read it. I don’t remember too much about the book, other than there being a blue skinned, gilled fish woman with a crush on Tom Swift and some kind of giant watery biodome aquarium in space. Or something like that. Also all the aliens have glottal stops in their names, because that’s how it was in the 80’s.