On a crisp September morning in 2025, the usually tranquil waters of Lake Tahoe became the stage for two extraordinary moments—one a gentle lesson in nature, the other a pioneering feat of science and technology. From a mother bear guiding her hesitant cub through a lakeside swim, to a team of conservationists and engineers plunging their custom-built robot to the lake’s mysterious depths, Tahoe’s recent stories are a reminder of both the lake’s enduring wonder and the urgent need to protect it.
It started with a heartwarming scene in the Tahoe Keys area, captured on video by local resident Jill Davis. Shared with KCRA 3 and published on September 12, 2025, the footage shows a mama bear calmly shepherding her young cub into the shallows of Lake Tahoe. The cub, much like any nervous human child learning to swim, quickly paddled back to shore—leaving viewers charmed by the familiar display of cautious curiosity and parental care. As KCRA 3 reported, the video offered a rare, up-close look at how wildlife interacts with Tahoe’s shoreline, a place where nature’s daily dramas unfold just out of sight for most visitors.
Yet, while the surface teemed with life and gentle lessons, something unprecedented was happening far below. On September 5, 2025, a remotely operated vehicle (ROV) named Emmy—short for Deep Emerald—descended 1,075 feet to the very bottom of Lake Tahoe. This marked the first time any machine or human had reached the lake’s deepest point, according to the Restore the Lake Depths Foundation. Emmy’s dive was not just a technical achievement; it was a window into a hidden world, livestreamed to thousands of viewers who watched in real time as the ROV’s cameras revealed the lake’s enigmatic floor.
Emmy is no ordinary robot. Built at a cost of nearly $50,000, she’s equipped with a custom 600-foot fiber optic tether, high-definition cameras, and even detachable hands to interact with the environment. The project, a partnership between Restore the Lake Depths and the Tahoe Fund, represents a new era in research and conservation for Lake Tahoe. As Caroline Grossman, development director for Restore the Lake Depths Foundation, explained, “There’s just a lot of different different hands in the pot of Lake Tahoe and the water conservation realm.” Funding and collaboration, she noted, are ongoing challenges in the effort to preserve the lake’s unique ecosystem.
For Brett Ferrari, the social media marketing manager for Restore the Lake Depths, the successful dive felt like “winning the space race.” The lead-up was tense, with concerns about water currents and unpredictable weather, but calm conditions on the day of the dive made for a smooth mission. The excitement was palpable as Emmy began her descent, a journey that had been two years and 20 practice dives in the making.
Lake Tahoe, the second-deepest lake in the United States, has long been a subject of fascination for scientists and locals alike. Yet, as Sudeep Chandra, a limnology professor with the Tahoe Institute for Global Sustainability at the University of Nevada, Reno, pointed out, the bottom of the lake remains one of its least studied habitats. “To see it is to believe,” Chandra remarked to the 3,200 people watching the livestream. He likened the lake’s anatomy to human organs, with the open water acting as a heart and the air shed as a brain. The bottom, he explained, is akin to the lake’s “lungs,” crucial for the ecosystem’s ability to “breathe.”
Despite its beauty, Lake Tahoe’s ecosystem is under threat. Chandra highlighted an alarming 85 to 99% decline in species at the bottom of the lake, a loss driven by excessive algae growth—referred to as “greening”—and the spread of invasive species such as crayfish and clams. These changes are not unique to Tahoe, but they serve as a stark indicator of how the broader environment is faring. Forests and meadows around the lake play a critical role in filtering sediment and reducing nutrient runoff, which in turn helps preserve Tahoe’s famous clarity.
Recent efforts to safeguard the lake include the launch of the Emerald Bay shuttles by the Tahoe Fund and Keep Tahoe Blue in June 2025. The new shuttle service aims to reduce air pollution in one of Tahoe’s most popular tourist areas, with the hope that cleaner air will translate into clearer water. As Amy Berry, founder of the Tahoe Fund, emphasized, “Everything we do in Tahoe is a partnership. You just can’t get very far alone around here.”
For the team behind Emmy, the dive was the culmination of years of perseverance and innovation. Technician Chris Holmes described the mission as both a personal and technical milestone. “What really drives us is the opportunity to bring people closer to something they’ve never been able to see before,” Holmes wrote in a statement. “The bottom of Lake Tahoe has been hidden from the public eye for so long, and now we have a chance to share that world—its mysteries, its beauty and its importance—with everyone.”
The technical challenges were formidable. Most test dives ended with Emmy returning to the surface battered and leaking, her cameras cracked and seals broken. Holmes admitted, “Testing didn’t get easier as we went—it actually got harder.” Traditional copper tethers for ROVs couldn’t handle the depths without causing video lag, so the team turned to a fragile but high-performing fiber optic tether custom-built by SeaView Systems. This innovation proved essential for streaming live 4K footage from more than a thousand feet below the surface.
Lindsay Kopf, founder of Restore the Lake Depths, had previously pulled 80 tires from the lake but had to master the controls of Emmy herself. She likened piloting the ROV to playing her “favorite video game,” but with far higher stakes. “We’re collecting footage that reveals the geology, biology and overall function of the lake,” Kopf said. “It’s a powerful tool for research, education, and protecting the lake moving forward.”
Looking ahead, Holmes believes Emmy’s dive will open new possibilities for collaboration and conservation. “Universities, research groups and organizations that haven’t had the resources or equipment to explore the lake at this level can now work with us,” he said. “We want to provide access and data that empowers education, research and conservation.”
Even as Emmy’s cameras illuminated the dark, silent world at the lake’s bottom, the shoreline remained alive with moments like a mother bear’s swim lesson—reminders that Lake Tahoe’s magic exists at every depth. With new knowledge and renewed commitment, those who love and study the lake hope to preserve its wonders, above and below the surface, for generations to come.