8 Photos That Will Make You Think Twice About Going Swimming

There's a lot lurking underneath the surface of the water, and these photos are cautionary tales if you're thinking of getting in.

The ocean covers 71 percent of the world, and much of it is unexplored and unknown. Even the parts we know give us reason to think twice about getting in.

Here are eight photos that will give you pause about jumping in the ocean. We don't want to scare you, but you should know what's lurking beneath those beautiful waves.

1. Unwelcome Visitor

There are 440 different species of sharks in the world today classified into eight different orders.

Some of them are very big while others are quite small. Some of them are to be feared while others mind their own business and are very calm. You may be surprised to learn that some of the largest species of sharks in the ocean are actually the nicest ones to encounter.

To prevent shark attacks, experts advise people to always swim in groups, avoid swimming at dusk when sharks are most active, skip the shiny or brightly colored bathing suit, and keep splashing to a minimum. If attacked by a shark, the general rule is "Do whatever it takes to get away!"

2. Seaweed Waves

We know this is a basically harmless phenomenon. These giant strings of seaweed aren't going to drag anyone down to the bottom of the ocean.

Still, they potentially have entire ecosystems living on them. We'd just as soon not get slapped with one of these massive plants.

3. Lion's Mane Jellyfish

This massive animal is the largest known species of jellyfish and the largest found specimen had had 121.4-foot tentacles! They live in cold waters and you likely won't stumble upon one unless you're trying to.

Surprisingly, the sting of this huge beast is seldom fatal but does leave redness and pain. The most frequent reason for stings are that a dead lion's mane jellyfish breaks apart and people accidentally bump into pieces.

4. Goblin Shark

This deep-sea species is sometimes called a living fossil. It looks so strange because it evolved about 125 million years ago.

Because it lives so deep in the ocean, it poses no threat to us. Just knowing this snaggle-toothed shark lurks around is enough to keep us on dry land.

5. Giant Anaconda

You know what sounds like a neat job? Wildlife photographer. Do you know what wildlife photographers do? This.

These guys really earn their money. They risk their necks and spend weeks waiting for the perfect shot. Luckily, they're rewarded with amazing photographs of animals we don't  normally get to see.

6. Octopus Love

We hope this octopus has good intentions. However, we wouldn't willingly give it a hug.

With their many suckers and strong arms, octopuses can pull apart clams and presumably humans. Attacks from octopuses are rare, but not unheard of.

7. Uh-Oh

This is one thing you don't want to see when you're surfing. A man-eater lurking in the very wave you're trying to catch.

While shark attacks on humans are rare, surfers are frequent victims when attacks do happen. Scientists think that sharks mistake surfers for seals when they are paddling their board out to waves.

8. The Abyss

The ocean has varied topography, just like dry land does. Somehow, this hole to who knows where is more terrifying because of its location underwater.

This free-diver took her chances and was rewarded with an amazing view and a tremendous photograph. Better her than us!