A mail boat called the J.W. Westcott II is used by the US Postal Service and has its own zip code: 48222. The boat is used to deliver mail to other ships on the Detroit River, and is the only floating post office in the world that delivers mail to moving ships. In 1895, the floating post office began ferrying mail to passing ships via rowboat, then updated to a 45 foot (14 m) ship in 1949. All mail can be delivered to crews on ships traveling on the Detroit River by being addressed "Vessel Name, Marine Post Office, Detroit, Michigan, 48222."
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