Before 15 August
Vessel-specific reference
Each vessel's median recorded offshore-to-inland duration was calculated using its completed pre-event voyages from July onward.
← Historical evidenceTaboneo–Banjarmasin
Exploratory researchCause unverified
Meridian · observed maritime behaviour
Taboneo–Banjarmasin
August 2026.
A retrospective study of longer recorded voyage intervals between an offshore anchorage and inland Banjarmasin, South Kalimantan. The data identifies an anomaly; it does not yet establish a shutdown, its cause, or a successful advance warning.
25
Matched vessels with pre-event history
22 / 25
Vessels with longer recorded intervals
+46.11 h
Median within-vessel duration increase
Matched-vessel result: offshore-to-inland voyages departing 15–18 August 2026 compared with each vessel's own median completed voyages before 15 August. Exploratory selection; the 25 vessels are not a random fleet sample.
Geographic context
A river-to-anchorage system, not an ocean crossing.
The comparison covers movements between Taboneo anchorage near Banjarmasin and the inland Barito-area dock. The 154-kilometre straight-line separation is not the navigable sailing distance. Recorded intervals may include waiting, cargo operations or voyage-boundary errors.
Offshore
Taboneo anchorage
3.66591° S, 114.48085° E
Inland
Banjarmasin / Barito
2.33754° S, 114.88151° E
What was observed
Of 25 vessels with usable pre-event comparisons, 22 had longer recorded voyage intervals during the event window. The median of the individual differences was 46.11 hours.
22 longer3 not longer
No validated cause. These are recorded voyage durations, not independently verified underway transit times.
Observation timeline
15–18 August 2026
Unusual departure cohort
A cluster of offshore-to-inland journeys took materially longer than the same vessels' earlier recorded intervals. The mechanism is not established.
August–September
Follow-up observation
Directional differences remained visible in exploratory monthly comparisons, but that alone does not show persistent congestion or provide predictive validation.
Weather screen
No obvious sustained offshore weather anomaly.
Sampled ERA5 measurements around 15–18 August showed offshore gust maxima of approximately 10.2–11.2 m/s and significant wave heights around 0.84–0.99 m. These observations did not reveal an obvious sustained offshore disturbance corresponding to the voyage-duration spike.
This does not rule out local storms, river levels, currents, tides, loading delays or navigation restrictions. Rainfall accumulation conventions and voyage-level exposure alignment have not been fully validated.
Evidence status and limitations
Observed: A retrospective directional change in recorded voyage duration across matched vessels.
Not established: A port closure, holiday effect, tidal restriction, causal weather link or specific congestion mechanism.
Not yet tested: Frozen-clock detection, prospective alert latency, out-of-sample predictive skill and AIS trajectory segmentation.
Sources: Voluspa core.voyages (2026 voyage completion cohort) and ERA5 atmospheric / ocean / forecast archives, analysed 16 October 2026.