It’s no surprise that training to be in an elite unit would be pretty punishing, and those who try to get into the US Navy SEALs are, on the balance of probability, not going to succeed.

Between 70 and 85 percent of those in each class will not succeed in their attempt to become a Navy SEAL, but they can pick up some useful things along the way.

What with the Navy SEALs being very aquatic they have to be sure they can survive in the water for extended periods of time.

You might think this is just a matter of relying on one’s natural buoyancy or by treading water, but neither of those options would cut the proverbial mustard.

That’s because they might have a bunch of kit weighing them down below the water, and treading water for extended periods of time is just too tiring. Instead, they are taught to do something called ‘drownproof training’, which prevents them from succumbing to exhaustion while keeping them above the surface of the water and able to breathe.

If you’re in the sea, then even the strongest swimmer is going to get hit in the face with a wave every now and then, so the person lays face down in the water. That might seem to contradict the whole ‘being able to breathe’ thing but they can keep themselves close to the surface and putting their head above the water to breathe when they needed to.

As long as you stay calm and keep your know-how, it’s a way of staying in the water while avoiding drowning and conserving energy.

While that’s part of the training, other bits of it attempt to bolster a person’s physical fitness and their ability to perform tasks in the water while restricted.

In one part of the training, potential SEALs have their arms and legs are bound so they can’t properly swim. They’re then they’re tasked with retrieving an object from the bottom of the pool with just their teeth.

That’s one of five tasks performed in a pool which is usually nine feet deep.

The drownproof training involves various stages, including tying candidates hands and feet together. (Richard Schoenberg/Corbis via Getty Images)

Other parts of the SEAL Water Challenge Test include bobbing up and down at the pool’s deep end 20 times and floating on their back for five minutes by arching their back and breathing deeply so the air in their lungs helps them float.

Elsewhere in their training is something called ‘hell week’, which pretty much consists of spending several days out in the cold and wet with barely a chance to sleep.

Much of the training is dangerous, and in February 2022 a candidate who had just completed ‘hell week’ died after becoming unwell.

According to the BBC, a report from the US Navy into the training process found that candidates were put ‘at significant risk’ of injury or death.