Sardine Run, the annual migration of billions of fish, is a big draw for predators (Credit: Lakshmi Sawitri/Flickr/CC-By-2.0)

In early February 2019, 51-year-old Rainer Schimpf and his team set out to film South Africa's famous Sardine Run off the coast of Point Elizabeth. The annual migration of billions of Sardinops sagax, more commonly known as South African pilchards or sardines, is a big draw for predators, especially the Cape gannet, a beautiful, cream-colored seabird, and the common dolphin. The two species work together to herd the large group of fish and separate them into smaller shoals known as bait balls, which are then scooped up by not just the birds and the dolphins, but also other hunters such as copper sharks and Bryde's whales.

In an attempt to obtain the best footage of the incredible natural phenomenon, which has been the subject of numerous documentaries, Rainer plunged into the middle of a swirling ball of fish. Suddenly the sea churned, and the experienced diver and his photographer Heinz Toperczer, who was filming from the boat, instantly realized something strange was going on.

Toperczer later told Barcroft TV, “As Rainer moved towards the bait ball, suddenly the water churned widely up, and I knew for sure that something was about to happen, so I held the focus of my camera on him firmly. Suddenly, dolphins shot out of the water, a white spray came out and then a whale appeared and grabbed him!”

A Bryde's whale feeding off the coast of Mexico’s Baja California peninsula (Credit: Brandon Cole/nwf.org)

While Toperczer was filming the terrifying turn of events with his video camera, Rainer, who was trapped head first and engulfed in darkness inside the whale's mouth, was trying to survive. “Nothing can actually prepare you for the event when you end up inside the whale – it’s pure instinct," the diver told Barcroft TV. “I held my breath because I thought he is going to dive down and release me much deeper in the ocean, it was pitch black inside."

Fortunately for Rainer, the whale quickly realized he was no sardine! “I felt enormous pressure around my waist which is when I guess the whale realized his mistake,” he said. “As the whale turned sideways, he opened his mouth slightly to release me, and I was washed out, together with what felt like tons of water, of his mouth, while the whale himself was swallowing all the fish in his throat.” Though the entire incident lasted just 1.8 seconds, it felt like an eternity to Rainer.

Still clutching onto his underwater camera, the diver swam to his boat, where he was quickly rescued by the members of the team, which included his wife, Silke. While most people would have refrained from heading back into the ocean, the harrowing adventure did not faze Rainer for too long. After checking to ensure he had no injuries, the diver returned to the water to seek out more bait balls. Fortunately, the rest of the expedition went smoothly.

Endemic to the Atlantic, Pacific and Indian Oceans, Bryde’s (pronounced "broodus") whales are members of the Baleen whale family. The mammals, which can reach lengths of up to 55 ft and weigh over 30 tons, are one of the "great whales," or rorquals, a group that also includes blue whales and humpback whales. The animals usually travel alone or in small groups, and feed on krill, shrimp, crabs, herring, mackerel, sardines, and anchovies. Just like other members of their species, Bryde’s whales are vulnerable to oceanic stressors and threats such as vessel strikes, ocean noise, and whaling.

Resources: huffpost.com, telegraph.co.uk,tripsavvy.com,animals.barcroft.tv