According to some embodiments, a document processing unit may receive information associated with a document to be processed. Remote controllers are connected to watercraft propulsion units. If an internal temperature of the tag is detected by the temperature sensor, the tag enters a sleep mode. Any client computer not meeting the policy is not permitted to access the Internet. The methods include directing a first jet of fluid along a first path and directing a second jet of fluid along a second path to cause interaction between the jets that forms a stream oriented essentially opposite to one of the jet paths. An extraction area is constructed around the region.