And, 45ft (14 metres) deep, this is where the father-of-two had his terrifying encounter with the humpback whale.
He told Cape Cod Times: “All of a sudden, I felt this huge shove and the next thing I knew it was completely black.
“I could sense I was moving, and I could feel the whale squeezing with the muscles in his mouth.”
At first, Mr Packard thought he had been swallowed by a great white shark.
But he could not feel any teeth and did notice any serious injuries.
It was then that he realised he was inside a whale.
He added: “I was completely inside; it was completely black. I thought to myself, ‘there’s no way I’m getting out of here. I’m done, I’m dead.’
“All I could think of was my boys — they’re 12 and 15 years old.”