I, sea : a tale told in homonyms
(Book)

"A swashbuckling tabby and their crabby first mate are enjoying a day on the water when—'Eye! Sea!'—a wave crashes against their ship and something gets in the captain’s eye. The two companions visit the optometrist, where the cat reads out the letters I and C during an eye test. The eye doctor explains, 'Eye. See?' and teaches the pirate how to put on an eyepatch. By the end of the book, readers will shout 'I see!' as it’s revealed that the whole story was part of a child’s bathtub playtime." --publisher's website.