Yeah, I noticed that the fish were somewhat randomly distributed. Do they change over time (say, with each storm) or is it static?
I like the idea of upgrading to higher tiers of boats, and that would translate into faster travel times as well, which would make things less monotonous. Although because it seems like you're going for an upgrade staircase of sorts, you'd want some sort of endgame or end goal to work towards other than "make more money."
A compass on the UI would be a pretty simple way of showing the way back. Maybe you have to buy one from the shop?
As far as the wave sounds -- I think the waves are still too loud. Not relative to the music (That part makes sense now) but just generally speaking.