Cast Away came out in 2000 and follows a FedEx employee called Chuck played by Tom Hanks. After his plane crashes, Chuck is left stranded on a deserted island completely alone. He must utilise rudimentary methods to survive.
Spearfishing becomes an integral way for Chuck to attain food. During his first days on the island he struggles to adapt to the conditions. This is due to the fact that he was previously used to a more comfortable and convenient existence. However, the film later flashes forward 4 years and we see a different version of Chuck.
He wears very little clothing and is sporting a long beard. He is also able to hit a fish with a spear with one throw from a fairly long distance. This shows that he has had a lot of practice over the years.
Spearfishing is a handy skill to learn in the unlikely event that you find yourself in a similar situation. You can craft a spear from tree branches or objects that might wash up on shore. Humans can survive for a long time on a diet of fish and using a spear is an ideal way of obtaining them.