A rock

Technology is great, until it is not.  Cases in point: a diver in scuba gear must be careful upon their return to the surface for they might get sick or even die from Decompression sickness (DCS; also known as divers' disease, the bends or caisson disease).  A condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurization.  Even once a diver surfaces they must wait before climbing to altitude or flying away.

In a World War I or II era sub seamen had to be careful not to turn their iron behemoth into a iron casket, at just few 100 Meters of depth the structure would fail and all aboard would be sent to a cold death in Davy Jones locker. 

The epitome of technology is a rock, by grasping a rock a freediver (like World champion freediver Guillaume Nery in the video above) was able to fall to the bottom of Dean's Blue Hole. It is the world's deepest known seawater blue hole Plunging 202 meters (663 ft) in a bay west of Clarence Town on Long Island, Bahamas.  This ability is possible due to the effects of Dalton and Henry's laws. Because the gas in his lungs are under increased partial pressure at depth, his body requires less oxygen to operate. In other words, the deeper you go, the longer you can go without breathing. Not to mention that 5 minutes of breath holding isn't unheard of.  And this is due in part to the greatest technology ever created: rocks, no science has been able to create matter, that is why a rock is the highest form of technology, ever.

What is it that makes a rock a rock, a stone a stone, and a pebble a pebble?  What is a pebble:  "Each pebble contemplates the sea and the tides, the currents and the storms, the mass of sister pebbles, flotsam and broken shells.  It is a passive synthesis of these events, a contemplating soul ground from repeated washes, like the limpet stuck to its side contemplating it in return: 'What organism is not made of repeated elements and cases, of contemplated and contracted water, nitrogen, carbon, chlorides, sulphates, other star stuff, thereby interweaving all the habits composing it?'"  All created at once, cycled, recycled, diving deeper while reaching out.

excerpts from: Gilles Deleuze's Philosophy of Time: A Critical Introduction and Guide