There is no better way to learn electronics than playing around with Raspberry Pi and Arduino platforms. This project from Erle Robotics shows you how to build your own aquatic vehicle with Pi Zero, PXFmini with WiFi dongle, HobbyKing Pod Racer Boat, and a controller.
Erle-Boat is a Linux-based boat. It uses the Ardupilot software for different navigation modes. More info is available here.