Three times in last two weeks between Barrier and Tauranga had weed foul prop. Never happened before. There was large clumps all over the place as result of big swells. Have folding 3 blade prop. Each time was able to clear by going to neutral to try to fold prop then hit reverse to the extent of making boat back up. Then back to forward. Each time prop cleared. This on sail drive. I think the weed folds around sail drive and you need to back up to remove it.