detroitjetaime.com. In Detroit mail travels on water! Sam and his coworkers operate onboard on the only floating zip code in the US, the J.W Westcott. In fact, these guys get their fair share of adrenaline daily. Their job is not just about handing out parcels to international cargos, it's also about saving lives... A moving depiction of these two men sailing between the US and Canada on the Detroit river, gateway to the Great Lakes.