marine animals

Why do whales swing their tails up and down, but sharks swing their tails to the sides?
why are they the same sea creatures, but the big whales swim in a way that swings their tail up and down and sharks and many other fish swing their tails sideways horizontally?
Unmanned aerial equipment can release floating rescue equipment at sea
after surfing off the coast of new south wales, two victims crashed to shore safely when a local lifeguard used an unmanned aircraft to give them a floating rescue device. sea.