I've been following a discussion on the A30 email list about bolts in the end of the boom that hold the sheet block and line. The A30 list doesn't allow pictures to be attached so I figured this was a good way to get a pix out there. I was at the boat yesterday and tried to figure out what the problem was and realized that some past owner had solved that problem on Slainte. Apparently the boats came from the factory with the sheet block attached to the end of the boom with a thru bolt. Over time that bolt will break. Not good if you are sheeted in with 15kns of wind!
This is the solution that a previous owner did. It would be my recomendation for all who still have the bolt in the boom.