One island, five live registers plus the field. This is the same instrument as the South Node observatory, pointed at the opposite pole. When every channel sits near its floor, the node is at rest — that is the baseline, not a null result. The reading that matters is what happens under drive: when the auroral oval climbs over the island and the planetary index rises, that is the window in which the sky's currents couple down into an all-sea coast.
Sources — Geomagnetic & aurora: NOAA SWPC (planetary K-index, OVATION nowcast). Seismic: USGS Earthquake Hazards Program. Sea state & weather: Open-Meteo (Marine + Forecast). Vessels: AIS Stream via the Magna backend. Magnetic field: NOAA EMAG2v3 compilation (survey).