If you an overlapping jib, you could put a stainless "hoop" guard around it.

It's strength plus line-of-site -- you can't cure a horizon-height deficit with a better reflector. If you do what you're talking about, you've got something only slightly better than a two large outboards ;^) If you mount that higher, you'll be seen for units to their limit for many more miles from freighters and to the limits of their power for small boats.