Five- year-old Tank was wearing a yellow life vest with the word 'gladiator' on it during the outing. His owners, Linn and Mark Lewis, say they suspect the Pomeranian fell off the boat near Goose Island on the north branch of the river. He weighs less than 10 pounds.
Tank's owners searched until 2 a.m. but couldn't find him. They are now offering a $500 reward to the person who finds him.
