With a stunning photo of the incident now making the rounds worldwide, the couple, who are South African sailing instructors, are describing their terror at the time and relief when they realized they had survived.
"Suddenly I saw this huge monster shape come up out of the water on my port side," Mothes said Thursday on NBC's Today show. "It just happened in an instant. It was quite frightening."
The young whale broke the boat's mast and damaged the cabin before falling back into the water, leaving behind barnacles, blubber and skin but no blood – suggesting it wasn't seriously injured.
Thankfully, neither were the humans, who were left to marvel at the incredible incident. "It was an awesome experience," Werner said, before quickly adding: "We wouldn't want to repeat it."