Rook & Tank in Trouble

"Rook looked up when he heard someone come aboard. He looked up from the map he was holding. A big, mean-looking vulture stood on the deck. "You're Rook!" Not a question. The soft voice didn't fit the look of the vulture. "Yes and who are you?" he asked. The vulture didn't answer him. He just stared at Rook. Then he said, "Your uncle owes us a debt. But since he isn't around anymore, you will pay us instead." "I hardly think that..." Rook began.
The vulture interrupted him: "Your uncle bet on seahorses and lost. A lot! We helped him pay his debt. 7 jars of raspberry jam. But interest and the hassle of tracking you down have made the price go up. 10 jars. It's okay if you pay a little at a time, but you will pay!" The vulture stared so intensely at Rook that it felt like it could see right into his brain. "But..." Rook said. The vulture took a single step towards Rook.
"Okay... OKAY!" Rook felt his whole body tremble. The vulture turned around and left.  Rook was trying to get a hold of himself, and now there was a new interruption. "Ahoy there! Permission to come aboard, " a booming voice said. Rook went to the railing to see who it was. On the dock stood the biggest Rottweiler he had ever seen. Not that he had seen that many, but this one was impressive. Broad chest, muscular, and handsome with paws bigger than Rook's hooves.
The brown eyes were intense but friendly. The Rottweiler smiled at him. "Hello?" Rook said. "My name is Tank, and I want to work for you", the Rottweiler said. "All I want in return is food and shelter. I'm good at what I do." "And what is it you do?" Rook asked. Tank grinned: "Everything that involves a boat!" Rook thought for a moment. He didn't know anything about boats, and Tank said he knew everything about them.
The only thing Rook knew was he needed all the help he could get."