Movies like 20,000 Leagues Under the Sea

The oceans during the late 1800s are no longer safe; many ships have been lost. Sailors have returned to port with stories of a vicious narwhal (a giant whale with a long horn) which sinks their ships. A naturalist, Professor (Pierre) Aronnax, his assistant, Conseil, and a professional whaler, Ned Land, join a US expedition which attempts to unravel the mystery.