another way is to look aft in your 19ft boat and see the hood is burning and flames are steaming 3ft behind the hood. that 19 ft boat gets about 3ft long instantly. dont ask how I know
Tie it to the side of the boat just like Old Man and The Sea!!
About 25 yrs ago I was in a canoe in a lake in Florida at my parents house and had a gator rise right along side. The gator was about half the length but looked much bigger!