Your ripped-up jeans with holes in the knees might LOOK cool.  But can they do this?  Two brothers from Germany recently took a job where they had to pick up a rich guy’s yacht in New Zealand, and sail it all the way to Brazil for him.

One of the brothers is 30-year-old Arne Murke.  And they were off the coast of New Zealand last Wednesday when the main sail knocked him overboard.  And he couldn’t get back to the boat.

His brother tried to toss him a life preserver, but he couldn’t reach it.  Then a huge swell carried him out to sea.

But he was able to survive . . . by using his jeans as a FLOATATION DEVICE.

It’s a trick they teach in the Navy.  First you take them off and tie the ends of the pantlegs together into a knot.  Then you pull them up and over the water to trap air inside, and hold the waist closed with your hands.  (The video above shows you how to do it.)

Once there’s enough air in there, you can stick your head through the legs, and use your jeans like a life jacket to help you float and save energy.  And if the air leaks out, you do it again.

Arne ended up floating around with his jeans around his neck for about three-and-a-half hours before the Coast Guard spotted him.  And the sea was pretty rough, so they’re not sure he would have made it without his jeans.

(NZ Herald / Sky News)