Eeee! A novel about characters under the sea! 8D An amazing story that reminded me of Moby Dick (which I will be reading for a 2nd time soon). It has the same author as Around the World in 80 Days and Journey to the Center of the Earth.
It's about these three men are brought on board a search for a great huge sea monster that turns out to be Captain Nemo's submarine. They are stuck with this dude and his crew, basically prisoners. Do they ever escape? That's for you to know if you ever read it. I'm not going to spoil it for you. Though I do know they spend a lot of time in the sea (obviously) and sometimes go to land, so it's not all sea. Though one scene that really stuck out to me was when the servant found something under the sea- a ruined ship with dead people around. You'll never be able to get that out of your head- trust me.