Answer: They were worried The Geats were there to invade Denmark
Explanation:
Beowulf was a warrior from Geatland who had come to help the Dane King Hrothgar, defeat a monster named Grendel who had been terrorizing the kingdom.
Beowulf and his 13 companions came in a very impressive ship wearing very impressive armour and tried to land without gaining permission from anyone. This alarmed the Dane Coast Guard who thought the Geats were there to invade Denmark.
