Trying to sneak back on board ship at three o'clock in the morning following a heavy drinking session ashore, a sailor was dismayed to find the chief petty officer waiting for him. With the sailor unable to provide an acceptable excuse for his tardiness, he was issued with an immediate punishment. "Take this broom," ordered the CPO, "and sweep every link on this anchor chain by daybreak." The sailor picked up the broom and started to sweep but as he did so, a tern landed on the broom handle. The sailor gestured at the bird to leave, but it refused to move. So he picked the tern off the broom handle and tossed it out of the way. However a few minutes later, the tern returned, once again alighting on the broom handle, and again the sailor was obliged to toss the bird overboard. This battle of wills continued throughout the night. Each time the tern landed on the broom handle, the sailor tossed it aside, only for it to come back a couple of minutes later. He was so distracted by the bird that he was unable to get much cleaning done as he could only sweep at the chain's links once or twice before the bird reappeared. As dawn broke, the CPO arrived to check up on the sailor's progress. He was not impressed: "What have you been doing all night?" he barked. "This chain is no cleaner than when you started! What do you have to say for yourself, young man?" "I'm sorry," said the sailor, "but I tossed a tern all night and couldn't sweep a link."