Throat blocks are the blocks that lift forward end of the mains’l and fores’l- one of our two halyards for each of our gaff sails. They are critical blocks and support a lot of load. Ours are all double blocks with one aloft and the other shackled to the saddle of the boom. Hauling on these raises the sail and tensions the luff- the leading edge of the sail. We have 4 throat blocks on the rig.