we once helped a slew of fishermen free two whale sharks that got cught in a weir off Grand Manan island in the Bay of Fundy. They were pretty big dudes and how they got together I have no idea. We were part of a small convoy that raised the netting I was one of two boats that had a porta cathead that we extended on a makeshift tripod. The really big boat was a scallop dragger so e all pulled on the nets and they came up high enough so that the bottom "tunnel was exposed and the sharks swam free.