I'm using my bike to commute between my work and home (~10km). In the middle of my trip I have to use a ferry and have to put my bike on the deck.
Within 2 weeks of the trip I could see my cassette and some nuts started to rust. Frame is aluminium and I didn't see any rusty spots on it. Since I've never used my bike this much in salty/humid environment I don't know anything how to protect it from rusting.
Is there any grease that I should use for nuts and other open steel surfaces to prevent rust?
Or should I just gently wash my bike every day after coming home ?