The clip shows the diver, Rich Horner, swimming at a popular spot, Manta Point, about 20km away from the famous island.
Horner, who permanently resides in Bali, said he had "never seen anything on this scale" before.
A diving consultant Adriana Simeonova reiterated this in a comment to the BBC, saying it wasn't a common sight in the area.
"We had visitors go out to Manta Point just one day before Mr. Horner did and they experienced beautiful waters," Simeonova said.