It depends of course, but generally marine equipment is extremely expensive and if you want maps for navigation/fishing with different data like tides, fishing

It depends of course, but generally marine equipment is extremely expensive and if you want maps for navigation/fishing with different data like tides, fishing areas and many others, you'll pay a yearly subscription for that map region, and it ain't cheap either. And that's just for maps. Add to this some cloud monitoring service that also will cost something.