This video says about itself:

Occurred September 26, 2013 / Ilha de Santa Maria, Açores, Portugal

This rare footage of a gigantic sunfish was captured on film by photographer Miguel Pereira off the coast of Portugal. The huge creature dwarfs the divers as it swims past. The slow-moving fish and clear water allow for some spectacular close-ups of this amazing animal.

“A few days before, my camera was damaged when the underwater housing flooded. The bad luck was compensated when diving with a GoPro I saw the giant Sunfish almost at surface level and practically static. The Sunfish seemed not to be bothered by our presence at all and followed us for 15 minutes.” -Miguel Pereira

From ScienceDaily:

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