The Setup
The identity graph tracks vessel relationships as time-bounded edges — ownership, management, flag state — each with a valid_from and, when the relationship ends, a valid_to. Over the last 180 days, ISM_MANAGER edges (the entity responsible for a vessel's Safety Management Certificate under the ISM Code) number 43,249, attached to 43,249 distinct vessels and 6,477 distinct managers. Zero of those 43,249 edges have ever closed.
The Chain
Zero-percent closure isn't unique to ISM_MANAGER. COMMERCIAL_MANAGER, the edge type for day-to-day commercial operation, carries 43,453 edges over the same window and has also never closed one. But two other relationship types in the same graph — OWNED_BY (51,450 edges) and SHIP_MANAGER (50,880 edges) — do close: 9.0% and 4.3% respectively. The difference isn't the relationship count or the vessel population; it's the start date. OWNED_BY edges began recording on April 2, 2026, and SHIP_MANAGER on April 18 — both have had four to five months to observe a manager or owner change. ISM_MANAGER and COMMERCIAL_MANAGER both started on July 9, giving them roughly two months. Younger relation types, unsurprisingly, have logged fewer closures — but ISM_MANAGER's 0.0% is still the sharper of the two zero-closure types by structure: every vessel in the ISM set carries exactly one edge — there is no recorded history of any vessel ever having had a different ISM manager.
Volume is also declining: 16,790 new ISM_MANAGER edges were created in the last 30 days, down from 24,782 in the prior 30-day window — a 32.3% drop in new-edge creation, even as the total vessel population with an ISM_MANAGER edge (43,249 of 65,285 tracked vessels, 66.2%) keeps growing slightly. Fewer new assignments are being recorded each month, and none of the assignments already on file have ever been superseded.
The average confidence-decay value attached to these edges is 0.900 — high retention, meaning the graph isn't quietly losing confidence in old ISM_MANAGER assignments over time even as they age without confirmation.
The Implication
ISM_MANAGER is the compliance-relevant edge type: it identifies who certifies a vessel's safety management system, which matters for flag-state audits, port state control, and — for vessels under sanctions scrutiny — for tracing whether a change in safety management correlates with a change in commercial control. A relation type where two-thirds of the tracked fleet has exactly one ISM manager on record, ever, with no visibility into reassignment, is a relation type that can currently only answer "who manages this vessel's safety now," never "has this vessel's safety management changed hands" — which is the more useful question for anyone screening for a shell reassignment or flag-of-convenience shuffle.
What to Watch
Whether ISM_MANAGER's first closure appears in the next 60–90 days, which would establish that the pipeline can detect reassignment at all rather than only ingesting new assignments. SHIP_MANAGER and OWNED_BY both took roughly four months to show their first meaningful closure rate — if ISM_MANAGER follows the same curve, closures should start appearing by late September or October. If they don't, the gap is architectural rather than a maturity artifact.
Limitations
Two months of history is not enough to distinguish "this relation type doesn't track closures" from "this relation type hasn't existed long enough to have any yet" — the comparison to OWNED_BY and SHIP_MANAGER is suggestive, not conclusive, since neither of those was measured at their own two-month mark for this analysis. The declining 30-day creation volume (16,790 vs. 24,782) could reflect a genuine slowdown in new ISM assignments, a slowdown in the ingestion pipeline itself, or normal noise in a metric with only six months of history — this piece cannot distinguish between those three explanations from the edge table alone.
Data as of 2026-09-08. Source: temporal_edges (Axiom Overwatch), relation_type='ISM_MANAGER', 180-day trailing window.