The term 'Threat at Sea' can be summarized by the 10-letter solution 'HAMMERHEAD'. HAMMERHEAD sharks are a species of shark that are found in tropical and temperate waters around the world. They are known for their distinctive hammer-shaped heads, which are used to detect prey. HAMMERHEAD sharks are considered a threat to humans due to their large size and aggressive behavior. They are also a threat to other marine life, as they are known to feed on smaller fish and invertebrates.