Fan is the protagonist of On Such A Full Sea and the character who we most often follow. She is described as “brighter than most, certainly less talkative, but otherwise, in terms of character, not terribly distinctive” (3). Physically, she is very small, being not quite five feet tall and of slim and slender build. Even at 16 years of age, she is the size of a girl of 11 or 12, which makes her perfect for her job as a diver in the fish tanks of B-Mor. Being slender and lithe, she moves fast and effortlessly in the water. She is described as moving like “a creature of prey, a sleek dark seabird knifing into the waters” (4). She also has the ability to hold her breath for two minutes or more, often pushing herself to attain greater lengths of time underwater to test her resolve.

She is a strong-willed and confident girl, showing throughout the book that she is willing to strike out on her own in the outside world, something that the normal citizens of B-Mor would never dream of doing. She is fearless, and her bravery is not because she is naive.