SoPac, or any place where you have a fringing reef and coral like Atolls or the Polynesian Islands less Hawaii.

My old boat's mast with steps is over 35 years old, all in the tropics, btw.

I wouldn't use sillycone. It's miserable stuff that is very hard to clean up, doesn't seal well and can permanently keep paint from adhering. Sillycone is for breast implants if you can't take your women straight.