Michael May's Adventureblog: Master of the Seven Seas
I agree entirely with the observation "So [I say to Disney], part two, Prince Caspian, didn't make a gazillion dollars. What a surprise. Prince Caspian was always the dud, relatively speaking, of the series. For fans who read and reread The Chronicles of Narnia, it was the one you could skip."
Oh, and it's frustrating I can't figure out how to italicize headers. Anyway...
The above link of MM also has the basis for his undersea colony.
Also see: http://michaelmay.us/09blog/06/0609_seahelmet.jpg