I have that blue sleeve on the front of my mast and it was put on by a rigger friend as he noticed a small crack in the mast. I wonder if yours is there for the same reason. It works fine but then I don’t put loads of prebend in the mast. Don’t bust your mast they’re expensive! Robert
The white hole protector looks like a pipe outlet flange. I have one on the outside of the boat for a pump albeit a bit bigger
If you start using chocks the mast is point loaded at deck level. It may be a good idea to fit that sleeve just as a precaution. If you order a champion version Wayfarer a sleeved mast is fitted standard by the builder. Maybe that is because racers tend to use chocks all the time?
There are ways to fix a small crack in the mast but a sleeve is NOT the way to do it.