Hello!
We are Triton, a student association based in Aachen. Our mission is to participate in the Microtransat Challenge, where the goal is to cross the Atlantic Ocean with a small, unmanned boat.
Navigating and communicating in the open ocean is far from straightforward. Mobile networks are obviously unavailable, and establishing a reliable radio link over thousands of kilometers is challenging, especially when one of the stations is as close to the surface as our boat. Thus, the best solution for us is satellite internet. Since our boat doesn’t require high data throughput, we don’t need bulky, power-hungry solutions like Starlink. Instead, we use Iridium’s Short Burst Data service with a RockBLOCK 9603 modem. But even with satellite Internet we will still have to see how reliable such a connection is, especially during rough weather.
For positioning, we rely on a GNSS module, but that’s not enough on its own. While it’s theoretically possible to determine the boat’s heading using GNSS velocity data, this method isn’t always accurate. To improve reliability, we also use an IMU, a single package containing an accelerometer, gyroscope, and magnetometer. This allows us to determine the boat’s heading with compass like precision.
And what about that black PCB? That’s our AIS receiver. All ships of a relevant size are required to broadcast AIS messages, which include information like position and heading, quite practical for collision avoidance. 
Finally, that even larger PCB with the USB ports? Sometimes, the processing power of a Microcontroller isn’t sufficient, so we have also integrated a Raspberry Pi Compute Module 5 on board.
And many thanks to Aisler for sponsoring the nice 4-Layer PCBs!