Greetings,
Mr. 43. I tend to agree with the potentially unacceptable abrasiveness of Magic Erasers BUT there is a place for them aboard.
Two other items I might mention...Even though your boat appears to be in fresh water, IF you have any rust or corrosion on your stainless steel, I highly recommend Spotless Stainless.
Spotless Stainless Home. Follow the directions and do NOT allow it to dry on the boat. Keep it moist by re-brushing.
Secondly, don't forget the cleaning powers of simple vinegar particularly if you can immerse or soak an item. I've de-rusted a number of rusty tools by letting them soak overnight in a vinegar bath. Good for removing water scale as well.
Oh, and...