I was wondering if someone (Steve) could elaborate on the 360 bases. What are they made of? Are they aluminum and carbon steel or stainless steel? I would really like to outfit my boat with some of these holders and bases except I am worried about rust. All steel will rust no matter what, but to make it worse I use my boat in saltwater, and in the Atlantic I have seen anything less than 316 SS rust to bits. I know there would be a smaller market but I would love to get some SS holders and bases. The extra $$ would be worth it.