My Light by Molly Bang discusses light and energy, all from the sun's perspective. The illustrations are absolutely beautiful!
We actually don't get into ocean explorers much. In fact, our TEKS (standards) changed last year (the year I didn't teach science) so I am not even sure if we will even talk about explorers. That being said, I came across this book last year (the librarian was giving it away as a freebie) and really enjoyed it myself. I just knew that if I ever picked up science again that I would use it in my ocean unit. The pictures are beautiful (common theme of the books I read!) and the story of Jacques Cousteau is told in an interesting and easy-to-follow manner.
(You may have noticed the two things I value in books--pretty pictures and easy-to-follow format! Keeps my kids' interest!)
I can't wait to see what books all of you post!