If you thought your two-hour soak in a tub gave you an exceptionally bad case of the pruney fingers, you won’t believe what 10 days of being under water does to your skin.

Tim Yarrow, a scuba diver, was featured in a recent episode of the Science Channel’s “Outrageous Acts of Science” about human guinea pigs after he spent 240 hours submerged — a world record.

Tim Yarrow Spent 10 Days Under Water Resulting in Pruney Skin

Tim Yarrow in a tank. (Image: Outrageous Acts of Science/YouTube screenshot)

Yarrow completed the feat in 2002 in a tank situated in a Johannesburg, South Africa, mall where he was observed in his experiment for a week and a half.

Yarrow was fed through a tube and went to the bathroom through a catheter. Breathing was performed using scuba equipment.

But after he got out of the tank, the effects of being under water for that long were not over.

Tim Yarrow Spent 10 Days Under Water Resulting in Pruney Skin

(Image: Outrageous Acts of Science/YouTube screenshot)

“That’s gross, did you see his hands,” one of the show’s hosts said.

Tim Yarrow Spent 10 Days Under Water Resulting in Pruney Skin

(Image: Outrageous Acts of Science/YouTube screenshot)

“It looks like he’s turning into some kind of fish person,” another host said.

Biologists on the show explained what was happening to his fingers.

“Skin on our hands and on our feet tends to get coarse. We have extra layers of dead skin because our hands and our feet are so well used,” Carin Bondair said.

These dead cells absorb water and become puffy.

They wrinkle because “there’s no where else for them to go,” another biologist said.

In 2011, TheBlaze reported on research that speculated pruneyness occurred to help primates better grip items in a wet environment. Ten days in water creates more than just a potentially functional level of wrinkly fingers though. Yarrow’s skin actually began to disintegrate, but in time it did recover.

Watch the clip:

(H/T: io9)