Video has emerged from the US of tourists having an incredibly close encounter with a humpback whale.

The footage, captured in September 26 at Puget Sound, Washington, shows a humpback whale swimming under the tourists' boat and surfacing before diving back into the sea.

The filmer says he and his friends had been diving a wreck in the area and while still at anchor they had spotted the whale in the distance.

His astonished reaction and that of his friends on the boat can be heard in the video.

''Look at that! He's coming our way,'' says one man on the boat.

"He is checking us out." says another.

Video has emerged from the US of tourists having an incredibly close encounter with a humpback whale.

After diving the wreck "Possession Point Ferry" and still at anchor we spotted a whale in the distance. The whale was headed in our general direction, but then it came right to us and circled the boat. This was a young Humpback Whale.