Cabo’s Underwater Sandfalls Are Slowly Fading Away

Near the famous Arch of Cabo San Lucas, one of the ocean’s most extraordinary and least-known phenomena quietly unfolds. Along steep underwater cliffs, sand flows like water, pouring endlessly into the deep blue canyons below. These are the sandfalls of Cabo — underwater cascades made not of water, but of sediment.

To divers, they look like gravity itself has come alive on the seafloor. Grain by grain, the sand slips over the edge, forming shimmering curtains that drift downward into darkness. Unlike rock or coral, these falls are never fixed. They exist only as long as sand continues to arrive.

For thousands of years, Cabo’s coastline naturally supplied them. Waves, storms, tides, and currents moved sand from beaches and shallow reefs toward steep submarine slopes. When the slope became too steep to hold the sediment, the sand gave way — creating the flowing cascades that made this place legendary among divers.

But sandfalls are fragile.

Today, many of Cabo’s famous sandfalls have weakened or vanished. The reason is not a single event, but a combination of shifting ocean dynamics and human influence. Changes in currents, stronger storms, and rising sea levels are altering how sediment moves along the coast. At the same time, harbors, dredging, seawalls, and coastal development interrupt the natural pathways that once fed these underwater rivers of sand.

When the supply is cut off, the falls stop flowing.

Some sandfalls now appear only after large storms. Others have moved deeper, beyond where most divers ever go. A few have gone silent entirely, their cliffs now bare rock where sand once poured.

Yet their disappearance tells a larger story.

Sandfalls are more than a visual wonder. They are signs of a living, moving coastline — proof that land and sea are constantly reshaping one another. When they fade, it reflects deeper changes in the health and balance of the marine environment.

To witness a sandfall is to see the seafloor breathe — a moment when the earth itself lets go and the ocean carries it away.

And in a changing world, that fleeting beauty matters more than ever.