On page 1 of the story, a SHADO technician tells Straker the UFO is headed for the Greenland Sea, a few miles north of Spitsbergen. Spitsbergen is an island in the Svalbard archipelago of Norway. The Greenland Sea borders it to the north and west.

In several panels of this story, the cockpit and tailfin of Sky 1 is missing from the top of Skydiver!

Skydiver 1 again uses its seaskim mode to travel rapidly across the ocean surface, as first seen in "Sub-Smash".

On page 6 of the story, the alien somehow knows Captain Carlin's name.

The fishing boat's first mate takes down the alien with the ship's harpoon gun and on the last panel of the story, he remarks to Carlin he is glad to know that SHADO is around to deal with the aliens whenever they attack. But the man will presumably be given SHADO's amnesia drug to make him forget the incident. 

UNANSWERED QUESTIONS

What about the dead alien body on the fishing boat? Will SHADO be able to learn more about the aliens from it? Or will the body disintegrate as others have in past stories? In "Arctic Affair", SHADO learned that arctic temperatures slowed down the rapid aging process of the aliens under exposure to Earth's atmosphere, so it would seem that if Carlin can keep the alien body on ice aboard Skydiver 1, they might have a viable body for scientists to study.