NOAA · EPA · USGS · Lakebed 2030
Live AIS for government and contracted research vessels, with historical tracks and automated detection of lawnmower grids and investigate turns (clover / “crazy-Ivan” style densification).
Lawnmower — repeated ~180° reversals at 2.5–9.5 kn (survey grid). Slow survey line — steady 3–9 kn for ≥12 min (mother-ship / DriX escort signature). Investigate clover — sharp turns inside ~1.2 km with high tortuosity (densifying a cell inside the grid). NRT / DriX often share mother-ship AIS or appear as NOAA/USV name hints only.