"At the beginning I thought, wow, I've got the All Blacks on the the boat but then I'd forgotten all about it later."
Mr Watson said the world champions were "just regular guys".
"The conversations I had with them are no different to what I'll say to my mates."
He said the recently retired captain had "one hell of a time" on the boat.
"I almost wished I wasn't filming so I could enjoy it more.
"Not that you can't have a good time."
Although it was down time for the boys in black, there was no shortage of competitive spirit on the water, and there were a few controversial calls.
"They had to photograph the fish as proof, as we release the fish at sea, but some photos went missing," laughed Mr Watson.
"There were accusations of players stealing each other's photos; rules were pretty loose," he said.
Mr Watson remained coy when asked who caught the least amount of fish.
However, he said Aaron Smith had a "blinder".
"He came away with a whole range of fish.
"He was the man of the match."
The North versus South competition came down to the wire, said Mr Watson.
The ITM Fishing Show episode featuring the All Blacks will be broadcast next year.