Consider this: We’ve all watched airplanes high in the sky. A plane flying 12,000 feet above you (that’s the average depth of the Indian Ocean) appears as just the smallest gray speck, its profile visible but indistinct. Now, imagine you’re looking down at that same plane. Except, you’re looking down not through clear sky, but through 12,000 feet of murky seawater. Indeed, for most of that depth you’re staring into aphotic blackness. And the airplane you’re looking for is, in all likelihood, no longer in the shape of an airplane; it’s in thousands of fragments scattered across miles of rugged seabed.