RCtestflight makes a lot of successfull autonomous boat/planes. i was wondering what GPS he used for the banana slug or the catamaran (the latest one) cause i could really get a close look
Really? This is a support forum for Ardupilot. Do you have a question about Ardupilot?
You can refer to this post (yours) for answers to the question of GPS modules:
a lot of his projects used the omnibus f4 but those are quite old and there are plenty other FC’s now that are of the same size but much more powerful. The matek H743 slim or any of those would work well. Its not the flight controller that matters and more is the understanding of ardupilot and its capabilities are. Take a look at the wiki its got loads of information.
Making a successful vehicle is not hard, its just a case of buying reliable, ardupilot compatible hardware (not questionable clones or really old tech which cant run the current fw.)
Then read the docs provided for the fw you install and you should have little trouble. You dont need to be able to do your own coding and you dont need a degree.