Snap-Back Zone Marking
Painted/marked deck areas indicating recoil danger from a parted line; revised guidance in MEG4 (2018).
In practice
Marked by deck cadets per MEG4 guidance; varies by line type and bollard geometry. Bosun briefs crew before each operation.
Regulatory detail & full definition
Painted or applied deck markings showing the recoil danger zone of a parted mooring line. OCIMF MEG4 (2018) revised the previous fixed-zone advice, recommending instead that operators identify the actual snap-back path using line geometry and crew positions during specific mooring operations rather than painting a generic zone. The change recognises that conventional snap-back zones gave false confidence — line behaviour after parting is harder to predict than the simple geometric arc once suggested. Crews still mark identified high-risk areas where personnel must not stand during line-handling.
Authoritative source: OCIMF MEG4 ↗
Related
Source: OCIMF MEG4
High confidence
Editorial confidence: how we grade.