I'm looking for a little "southern" information for my son who moved to Florida this past April. He lives in Melbourne, right on the beach, and has two of his hunting guns down there with him. He was telling me that every time he looks at them, he has to wipe surface rust off them. He said he keeps them oiled quite heavily and they still show some surface rust. What is the secret to keeping them rust-free in that humidity, and I'm sure the salty environment has a lot to do with it too.

I lived in Melbourne for almost 2 years. Pahran and South Yarra.
He could try a gun cabinet with a wood linning. Also a couple of bags of moisture absorbent. Alternate one in the cabinet and one in the hot water cupboard.
May also look at changing his gun oil.