National Geographic : 1941 Mar
384 The National Geographic Magazine Two Fins Moving in Line Betray the Broadbill to the Lookout Visible on calm days to distances sometimes exceeding a mile, the dorsal and caudal fins give the giant away as it lies circling upon the surface. The space between the two is often nearly six feet. The one in front always remains erect, while the tail sways slowly from side to side. "Greyhounding," the Marlin Clears the Water in Low, Fast Jumps Such action creates a large "belly" in the line, taxing the angler to the utmost to keep it from breaking. The thin strand would be snapped if suddenly jerked taut.