We approached the rim of the cliff cautiously. Five pairs of eyes peered over the edge and searched the dark water, but the vast expanse of the wall below us disappeared into a void of indigo blue. One by one my four companions and I jump off and begin our descent. Water visibility excellent, 50 plus at least. Pausing to take some photos, I lose sight of my dive buddies, but follow their trailing bubbles until they stop at 130 feet. We find ourselves in an aquatic limbo. The bottom is 1,000 feet below and the surface, hidden by the granite wall, looming above. We are miles from any ocean, diving in the crystalline water of Lake Tahoe. Before us is the immense underwater precipice known locally as the Rubicon Wall.

Located at Bliss State Park on Tahoe’s southwest shore, we followed a steep trail leading from a small parking lot to the secluded beach of Calawee Cove. Snorkeling parallel to shore we submerge after leaving the rocky peninsula of Rubicon Point and head into deeper water. The contour of the lake dropped with every foot of water we descended until the bottom suddenly disappeared below us at the rim itself.

Tahoe is 6,229 feet above sea level and is considered a high altitude dive. We may have been at a measured depth of 130 feet but, physiologically, with the complications of altitude, we were at 162 feet. Watching the readouts on our dive computers carefully to avoid getting the bends, we lingered for only 15 minutes, enjoying every second of our unique situation. Tahoe is also one of the deepest lakes in the world. All our equipment was carefully tethered and my camera secured by a nylon strap to a D-ring on my BC. If we dropped anything on our dive it wouldn’t stop until it hit the bottom of the wall, 1,000 feet blow us. The darkness of the water seemed to add to the lower temperatures at depth and I was glad to be wearing heavy insulation in my dry suit.

We ascended slowly, exploring the wall as we went. The rock was rough and fractured, its surface studded with milky quartz crystal. A fine layer of silt covered its surface and we had to be careful that an accidental brush of a hand or motion of a fin would cut our visibility down to zero.

The only marine life we saw during our ascent was limited to the crayfish that scuttled up and down the cliff face. Catching one, it raised its ragged toothed claws in defiance waiting for any opportunity to catch a misplaced finger. Dark green eyes stared at me from the rough shell of the carapace and its segmented antennae waved up and down through the water. When I released my grip, the little crustacean climbed around my gloved hand, pausing on the tip of my index finger before swimming away in lobster fashion, finding sanctuary within a deep crack.

As we neared the top of the wall, the rays of the morning sun began to reappear, illuminating a school of tiny fingerling trout swimming along the edge. Except for the crayfish, they were the only life we had seen. Pulling ourselves over the top, the little fish part like a living curtain as we enter the daylight. Winding our way through a field of massive boulders we reach the sandy bottom of shallow water. Our gauges read at 10 feet and we stay at this depth until we reach shore to ensure decompression. Swimming northward, we follow a thick, black telephone cable running parallel to shore. Above us, snorkelers wave as they swim toward Rubicon Point. Kayakers skim along the surface, their paddles making bubbly halos as they dip into the water. Tall ponderosa pines standing along the shoreline seem to move with the shimmering current, reminiscent of the kelp forests along the California coast. Surfacing near the waters edge of Calawee Cove, we break the surface and remove our regulators. The pine scented air smells sweet after the metallic taste of a scuba tank.

Being the last to arrive, my companions wade in the shallow water while I remove my mask and fins. The slow pull of gravity makes us heavy as we leave the water and the climb back up the trail to our cars feels like Mount Everest. It was a small price to pay for the experience we have had.