Bulwagga anchors are great in hard bottoms, though they were designed to
work well in heavy weed. Ours held in some extremely hard bottoms in the
Caribbean where almost nothing else would. They are named after Bulwagga Bay in Lake Champlain, which is very weedy. They are great in weed too. Unfortunately, they are not currently available new. You might be able to find one in the classified ads on this site or other
marine sites.