Check the electronics - equipment manuals and spares
The navigator is often responsible for the operation and maintenance of the electronics. It pays to be ready to do the job without the electronics, or to be able to fix it – or both. Even if the repair requires an engineer, it still pays to have a full understanding of the system – as the more information there is about a problem the faster a fix will be.
The spares and manuals carried onboard will depend on the length of the race, the size of the boat and the electronic engineering talent of the navigator or other crew members.
I always switch everything on as soon as I get to the boat before racing, and then I check that all the sensors are sending data that makes sense – particularly GPS, compass heading, boat speed, wind speed and direction – and that everything that should be networked is still networked.