have not met them says the writer talking about the tow-lines. to what kind is he referring ? what is his general opinion about tow-lines?

After tea, George tows the boat from the shore. According to J., the last few hours of towing are always the most difficult. He remembers going boating with a female cousin. When towing the boat at the end of the day, they got lost, only to be saved by a group of working-class locals.