I read the book about 3–5 years ago, though that doesn't mean much as the book felt very old.
The book had a blue cover with a silhouette of a boat floating in front of an orange sun right on the front. The style of art seemed older to me.
The plot involves a human empire that colonized many planets, including a planet that was covered in water. There was a spaceport on the planet but due to the planet's location and lack of useful resources nobody ever stopped in and the spaceport fell into disrepair, stranding the human population left there. The humans had to assimilate themselves into the native inhabitants’ lifestyle, known as the "Gillies". They didn't speak the same language, but tolerated humans because of their medicinal knowledge and cheap labor. After a few decades, the Gillies found out about a human who was capturing native intelligent fish for testing. They grew angry and forced the humans off the floating settlement.
So the humans had to take to a ship and set out to find... the spaceport? Dry land? One of the poles? I forget where they were heading. It ends tragically, if I remember correctly.
I don't remember the protagonist at all, other than that he was male and was related to a Doctor who had come to the planet years before and gave medicine to the local alien population, the "Gillies".
The name and author both escape me (obviously) but I believe it was called something like:
- Coastal Waters
- The Water's Edge
- Coastal Edge?
I'm very vague on the name.
Any help will be greatly appreciated! I've been dying to re-read this book. It's driving me crazy.