No air
Even if your scuba gear is ready to go, that doesn’t mean you should let your guard down. Remember, when diving, anything can go wrong, but as long as you keep your wits about you, you’ll most likely make it out of any sticky situation mostly intact.
This guy and a buddy were 110 feet below the surface of the ocean before they realized how far they’d gone. Yeah, that’s a pretty stupid mistake, considering they only had a spare tank that was good for about 45 breaths. Luckily, they made it out okay, but they probably learned a very important lesson about paying close attention to how deep they dive.