returning from lymington to hamble last weekend, running in 20knts of wind with full sail we had the backstay tensioner shackle bolt fail with a bang and a certain apprehension that we may have lost the mast. We rounded up, dropped sails and returned to port safely. Was this luck or were we in danger of a dismast? Anyone else had problems with shackle failures? should I replace all with Proboat fittings?