Four men from Perth went on an annual fishing trip in Coral Bay, Western Australia when they had an unexpected close interaction with a giant shark Wednesday.

The horrifying interaction was caught in a video, which shows a massive whaler shark close to 10-foot long chomped on the boat's propeller. It is not the first shark attack incident since a similar event happened in Perth when a 14-foot (4.2 meters) great white shark attacked a family boat last month. So, why do these marine apex predators attack boats?

A diver clings 16 September to the side of a cage
(Photo : ANNA ZIEMINSKI/AFP via Getty Images)
A diver clings 16 September to the side of a cage towed by a powerboat, as a five meter (yard) Great White Shark thrashes its tail while it attacks bait thrown to it off the coast of Gansbaai, about 100 kilometres (63 miles) from Cape Town.

Fishing Trip Gone Wrong

The four fishermen had the fright of their life when a 9.8-foot long bronze whaler shark approached their boat and bit its propeller. The shark had been fighting on a line for an hour before it decided to attack the motor of the boat, local news outlet 9News reported.

"He is a monster," one of the four men can be heard saying in the video. While another one also exclaimed, "Oh man, this is nuts." 

According to the group, the shark had taken a liking to the engine and hung on there for a few minutes as it chomped it down.

They started getting worried about how they were going to get rid of the shark since the apex predator seemed to have no plans to leave the motor. 

Jarryd England, one of the four men on board the ship, said that the beast's jaw inhaled the entire propeller, given the engine's massive size.

Fortunately for the group, the terrifying encounter only lasted five minutes because the shark eventually decided to let go and swim away from the boat. 

The fishermen and shark were unharmed following the terrifying encounter.

ALSO READ: Shark Bites Fisherman in the Bahamas, Coast Guard Airlifted Victim to Save Him From 'Terrifying Situation'

Man Falls Off From Paddleboard After A Shark Attack

The terrifying encounter between the four fishermen and the whaler shark came weeks after an Australian YouTuber had a close call with a tiger shark, who bit his paddleboard. Broddie Moss, who runs the YouTube channel YBS Youngbloods was enjoying the open sea on his paddleboard when a shark chasing a turtle came near him, MailOnline reported.

At first, Moss was only observing the encounter between the two marine animals. However, the tiger shark suddenly turned around, raised its head, and bit the paddleboard, causing him to fall off his paddleboard and into the ocean.

It was indeed a terrifying moment, but luckily, he was okay and reminded people that it was also not the shark's fault since it was their natural habitat and people should be respectful and careful when out there.

Why Sharks Attack Boats and Inanimate Objects?

Fishermen have told tales about sharks trying to eat boat engines and the recent videos support those claims. According to Seeker, sharks are attracted to electrical pulses emitted by some boat motors.

South Carolina Aquarium Shark Expert Arnold Postell explains that sharks can detect electromagnetic fields with their jelly-filled pores at the tip of their snout designed to pick up even the slightest electric pulses, like the muscle contractions of their prey. The boats' engines give off electric pulses similar to marine animals confusing them.

Another probable reason is the shark thinking that it's targeting potential prey. The shark bites to see if the item is worth eating. After all, the vast ocean also has extensive food options.

Below is the video of the encounter of the four men with the giant shark in Western Australia:

 RELATED ARTICLE: 14-Foot Great White Shark Attacks Family Boat After Circling It For Over An Hour; How Often Do These Predators Attack? [WATCH]

Check out more news and information on Shark Attack in Science Times.