RNLI LIFEBOAT B 851 — SAR · MMSI 235087721

RNLI LIFEBOAT B 851 has not broadcast an AIS position for 3 days. The most recent broadcast placed it in the North Sea, on 5 Nov 2026, 15:37 UTC. It was sailing from ROSYTH to HAWES PIER. Vessels stop appearing on terrestrial AIS when they move beyond receiver range, so a gap does not necessarily mean the vessel is inactive.

RNLI LIFEBOAT B 851 broadcasts MMSI 235087721. The MMSI is the radio identifier used by AIS; the IMO number stays with the ship for life and does not change with re-flagging or sale.

RNLI LIFEBOAT B 851 is classified as a sar vessel registered under the GB flag. The vessel-type classification is derived from the AIS Type field broadcast by the ship's transponder; full sar fleet at /vessel-type/tug-pilot-vessel and full GB flag list at /flag/gb.

MarineRadar shows the latest AIS broadcast from RNLI LIFEBOAT B 851 above, with current position, course, speed, and navigation status. Tap "View on map" to centre the live tracker on the vessel and watch its movement update in real time. The same data is available offline-friendly in the iOS and Android apps.

AIS transponders broadcast position every 2 seconds when underway at high speed and up to every 3 minutes at anchor. The position you see refreshes whenever the ship is in range of a coastal AIS receiver or a satellite pass — typically seconds in coastal waters and minutes offshore.

As a sar, RNLI LIFEBOAT B 851 sits in the same design class as the other sars listed in the Similar Vessels section of the vessel page, or in the full sar directory at /vessel-type/tug-pilot-vessel.