{"id":1014,"date":"2026-07-22T22:32:14","date_gmt":"2026-07-22T22:32:14","guid":{"rendered":"https:\/\/synmax.com\/maritime\/?p=1014"},"modified":"2026-07-30T02:14:56","modified_gmt":"2026-07-30T02:14:56","slug":"how-to-identify-and-investigate-ais-gaps","status":"publish","type":"post","link":"https:\/\/synmax.com\/maritime\/how-to-identify-and-investigate-ais-gaps\/","title":{"rendered":"How to Identify and Investigate AIS Gaps"},"content":{"rendered":"\n
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Fig 1. The moment a track stops is the moment the investigation can start.<\/figcaption><\/figure>\n\n\n\n

An AIS gap is a period during which a vessel that normally transmits stops appearing in the AIS record and later resumes. Because the AIS baseline is the reported picture of who is where, a gap is a hole in that picture, and holes are informative. A vessel that wants to conceal an activity often creates one. The analytical challenge is that not every gap is deliberate. This guide covers how to identify gaps in the baseline and investigate what they mean.<\/p>\n\n\n\n

Step 1: Define what counts as a gap<\/strong><\/h2>\n\n\n\n

The first task is establishing a baseline rhythm. A vessel’s normal reporting cadence depends on its equipment, its route, and the coverage in the area it transits. A gap is a deviation from that expected rhythm: a silence longer than the vessel’s own pattern would predict. Setting the threshold well matters, because too loose a definition floods the analyst with noise and too strict a one hides real concealment.<\/p>\n\n\n\n

Step 2: Separate benign gaps from suspicious ones<\/strong><\/h2>\n\n\n\n

Many gaps have innocent explanations. Reception is uneven, receivers have limited range, equipment fails, and dense traffic can cause message collisions. Before treating a gap as intentional, the analyst weighs several factors:<\/p>\n\n\n\n