Callsign:	WDK4147
MMSI number:	367085890
Navigational status:	Under way (engine) (0)
Vessel class:	Tug (52)
Location:	37°51.22' N 122°23.16' W - locator CM87TU34QV - show map 6.6 km East bearing 110° from Tiburon, Marin County, California, United States [?] 8.7 km East bearing 94° from Sausalito, Marin County, California, United States 9.2 km North bearing 19° from San Francisco, San Francisco County, California, United States 71.7 km Northwest bearing 323° from San Jose, Santa Clara County, California, United States
Last position:	2025-10-29 07:22:09 UTC (77d 14h34m ago) 2025-10-29 00:22:09 PDT local time at Tiburon, United States [?]
Course:	317° – heading 511°
Speed:	9 km/h
Last path:	WDK4147>ais via SUNSET
Positions stored:	1088

This page shows real-time information collected from the Automatic Position Reporting System Internet network (APRS-IS). APRS is used by amateur (ham) radio operators to transmit real-time position information, weather data, telemetry and messages over the radio. A vehicle equipped with a GPS receiver, a VHF transmitter or HF transceiver and a small computer device called a tracker transmits it's location, speed and course in a small data packet, which is then received by a nearby iGate receiving site which forwards the packet on the Internet. Systems connected to the Internet can send information on the APRS-IS without a radio transmitter, or collect and display information transmitted anywhere in the world.