Brittany Brock said the whale shark was so massive and accompanied by so many smaller fish that it resembled "a rolling cloud" that was "larger than a school bus."
The rare, magical encounter with a sea creature measuring perhaps 35 feet occurred Sunday off West Palm Beach, Fla., as Brock was scuba diving with her husband, Keith Brock, her 13-year-old cousin, Addie, and their guide, Craig Buss.
"I heard my husband yelling over his regulator and looked up to see a what looked like a rolling cloud," Brock told GrindTV. "There were cobia and remoras everywhere – then I realized they were attached to something, and that something was a whale shark!"
Whale sharks are the planet's largest fish and can reach lengths of about 40 feet. Fortunately for humans, they're filter feeders that subside on plankton and tiny fishes.
Brock and her group had been diving with Pura Vida Divers at spot called The Trench, and had begun its ascent ascent when the whale shark materialized in the distance.
"They are rare in Florida," Brock said. "People dive their entire lives and never get to witness that."
Making the experience more surreal were the remoras and cobia attached to or swirling around the whale shark. (Remoras attach to sharks and eat parasites and other organisms from the skin of host animals.)
"Our teeth were chattering," Brock said. "The whale shark swam right at us, and then through us. Such a gentle giant. He barely had to flick his tail (which was much taller than me) to gracefully glide through the water.
"When he started to swim away we all just looked at each other in total disbelief. It was the most amazing experience I’ve ever had diving!"