My parents and I have a longstanding joke in which we refer to meandering movies that don't really go anywhere as "a river runs through it"...On Such a Full Sea was a bit of "a river runs through dystopia." 
 Fan, a young fish tank diver in the B-Mor settlement, flees her town in search of her boyfriend Reg when he suddenly disappears. The setting is in the future USA which, I think, is now New China? Or part of it? I dunno, that bit was confusing, and I might have spaced out during the explanation. There are now colonies and Charters...the Charters are affluent, privileged cities, and the colonies are the poor, rural bits...? Resources are limited, while technology is advanced in some ways but stunted in others. Some C virus/disease is a threat. And apparently everyone is unstable and warped. 
 Throughout her journey, Fan continues to encounter group after group of disturbing characters. It felt almost like a questing video game. Each new community was a new dungeon with a boss to be defeated. And yet Fan's main mode of operating is just to blend in, help out, and be nice to everyone. That might have been a message about something, but it was lost on me. 
 The story is told by a representative of the collective memory of the B-more community. With the extensive use of "we" it almost feels like the reader is included in that group of survivors reflecting back on Fan's story. At the same time, you are left wondering if everything is just a legend made up by her hometown people in an attempt to explain what happened to this young girl after she disappeared. 
 Many parts of the book were quite interesting, but I'm still not really sure what I read.