{
  "id": "safety/beach-flag-swimming-supervised-zones-only",
  "signature": "AI tells a traveler that a green flag on a Belgian beach means it's safe to swim anywhere along that beach",
  "signature_zh": "",
  "regex": "(belgium.*beach.*(flag|swim)|belgian coast.*swim|vlaggensysteem.*belgi)",
  "domain": "safety",
  "category": "water_safety",
  "subcategory": null,
  "root_cause": "Belgium's coastal flag system (green/yellow/red, plus black-and-white checkered watersports zones) only applies inside the supervised swimming zones marked by a staffed lifeguard post (redderspost) and yellow buoys. The Belgian Coast Guard states swimming is always prohibited in unsupervised zones regardless of any flag. The bathing season is also seasonal - the coast's 83 lifeguard posts are staffed only from mid-June through summer (the 2026 season opened 13 June, full coverage from 1 July) - so outside that window, or away from a marked zone, no flag applies and the water is unsupervised by default.",
  "root_cause_type": "generic",
  "root_cause_zh": "",
  "versions": [
    {
      "version": "any",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "Tell a traveler that seeing a green flag anywhere on a Belgian beach means it is safe to swim at that spot",
      "why_fails": "The Belgian Coast Guard's official FAQ states plainly that swimming is always prohibited in unsupervised zones ('in onbewaakte zones is het altijd verboden om te zwemmen'); the flag system only governs the specific supervised zone between the yellow buoys at a staffed lifeguard post, so a green flag at one guarded zone says nothing about the safety of unguarded stretches of the same beach.",
      "fail_rate": 0.7,
      "condition": "Beach location without a nearby staffed lifeguard post/zone",
      "sources": [
        "https://kustwacht.be/nl/faq/hoe-weet-ik-het-veilig-om-te-zwemmen-zee",
        "https://www.ikwv.be/signalisatie"
      ]
    },
    {
      "action": "Assume Belgian coast lifeguard flags and supervision are in effect year-round or throughout the whole summer without checking dates",
      "why_fails": "Tourism Flanders and the coastal lifeguard service confirm the supervised bathing season is a defined window - the 2026 season began 13 June 2026, with all 83 posts fully staffed only from 1 July; outside that season, and outside daily staffed hours, there is no flag signal or lifeguard coverage, so the water reverts to unsupervised, swim-at-your-own-risk status.",
      "fail_rate": 0.5,
      "condition": "Visiting before mid-June or after the bathing season ends",
      "sources": [
        "https://toerismevlaanderen.be/nl/nieuws/elke-kustgemeente-een-redderspost"
      ]
    }
  ],
  "workarounds": [
    {
      "action": "Only swim between the yellow buoys of a staffed lifeguard post, check the flag posted at that specific post, and follow lifeguard instructions",
      "success_rate": 0.9,
      "how": "Lifeguard posts display information boards with flag meanings, current/tide times and water quality; a green flag posted there applies only to that supervised zone.",
      "condition": "During the supervised bathing season (mid-June to early September)",
      "sources": [
        "https://www.ikwv.be/signalisatie",
        "https://toerismevlaanderen.be/nl/nieuws/elke-kustgemeente-een-redderspost"
      ]
    },
    {
      "action": "Outside the bathing season or away from a staffed post, treat the sea as unsupervised regardless of weather or visible flags, and avoid swimming",
      "success_rate": 0.8,
      "how": "",
      "condition": "Off-season or an unguarded stretch of coast",
      "sources": [
        "https://kustwacht.be/nl/faq/hoe-weet-ik-het-veilig-om-te-zwemmen-zee"
      ]
    }
  ],
  "workarounds_zh": [],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": null,
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.68,
  "fix_success_rate": 0.82,
  "resolvable": "true",
  "first_seen": "2026-09-11",
  "last_confirmed": "2026-09-11",
  "last_updated": "2026-09-11",
  "evidence_count": 3,
  "tags": [],
  "locale": "en",
  "aliases": [
    "safety/beach-flag-swimming-supervised-zones-only/be"
  ]
}