Visuals and audio are really well-done; the first ship moving slowly was a bit annoying at first, but it really helps with the atmosphere of the whole experience and makes getting new ships that much more satisfying. Graphics and premise are also well-done and on-theme. Having voice acting for the old keeper was also a nice touch.
Controls could use a little bit of work, though - navigating the map before getting the zoom function is a touch too slow on mouse/keyboard in my opinion, and ships moving while in other interfaces makes it much more likely to accidentally crash, especially when transferring to/from the lighthouse. (Selecting a new ship to move it a touch closer to the lighthouse in order to load it up with gold, then selecting lighthouse while not realizing you still had the ship selected would often just send it happily sailing directly into the lighthouse, which was pretty frustrating while still learning the ropes of the game.)
I think I also ran into a bug. My ships would occasionally merge with one of the towns to the south and I couldn't drive them away - trying to click to select the ship just opened the town interface. I think this is because the ship got entirely overlapped by the "open town interface" area, but that still seems like something that shouldn't be happening.
Overall, good work! This seems like it has a lot of space to grow with some more time put into it, and I'd love to see how that goes if you go down that route.