Check out the
Australian Kayak Fishing Forum for info on mods to fiberglass fishing skis. Search in the Do It Yourself and Rigged Kayak forums. The Stealth skis are the most popular in Oz, but the mods should be similar for the Macski.
You should also try the South African fishing ski forums and manufacturer websites.
Kayak Fishing South Africa
Fishing Ski Forum at the Fishing Corner website