{
  "id": "safety/yellow-flag-swimming-prohibited",
  "signature": "AI tells a beachgoer in Portugal that a yellow flag just means 'swim with caution', so swimming is still allowed if they are careful",
  "signature_zh": "",
  "regex": "(yellow flag|bandeira amarela).{0,40}(swim|portugal|caution|allowed)",
  "domain": "safety",
  "category": "legal_misconception",
  "subcategory": null,
  "root_cause": "Under Portugal's national beach ordinance (Edital de Praia, enforced by the Autoridade Maritima Nacional), a yellow flag does not mean 'swim carefully' - it legally prohibits swimming beyond wading depth. Only wading near the shoreline is allowed. Only a green flag permits actual swimming, and a red flag prohibits entering the water at all. Violating the flag is a fineable offense (55-550 EUR).",
  "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": "Swim out past the shoreline / go for a swim when a yellow flag is flying, reasoning that yellow just means 'be careful'",
      "why_fails": "Portugal's Edital de Praia defines yellow as 'cuidado e proibicao de nadar' (caution AND a prohibition on swimming) - swimmers must stay where they can stand and must not swim laps or head away from the shore. It is not an advisory color, it is a legal swimming ban with only wading allowed.",
      "fail_rate": 0.75,
      "condition": "",
      "sources": [
        "https://postal.pt/nacional/autoridade-maritima-alerta-banhistas-proibido-fazer-isto-quando-bandeira-amarela-praia-multas-podem-ultrapassar-500-euros/",
        "https://www.rtp.pt/noticias/pais/multas-para-banhistas-que-entrem-na-agua-com-bandeira-vermelha_n30397",
        "https://www.amn.pt/Documents/Editais%20Praia/Edital%20de%20Praia%20-%20Continente%20e%20Madeira%20-%20Lingua%20portuguesa.pdf"
      ]
    },
    {
      "action": "Enter the water at all when a red flag is flying, planning to just stay in the shallows",
      "why_fails": "Red 'assinala perigo e determina que ninguem deve entrar na agua' - it bans entering the water entirely, not just swimming, regardless of how shallow the intended spot is.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": [
        "https://postal.pt/nacional/autoridade-maritima-alerta-banhistas-proibido-fazer-isto-quando-bandeira-amarela-praia-multas-podem-ultrapassar-500-euros/",
        "https://www.rtp.pt/noticias/pais/multas-para-banhistas-que-entrem-na-agua-com-bandeira-vermelha_n30397"
      ]
    }
  ],
  "workarounds": [
    {
      "action": "Treat yellow flag as 'wading only, no swimming' and red flag as 'stay out of the water entirely'",
      "success_rate": 0.9,
      "how": "Only enter the water past ankle/knee depth when a green flag is flying. Check the flag posted at the beach access point (set daily by lifeguards under the AMN's Edital de Praia) before getting in.",
      "condition": "",
      "sources": [
        "https://postal.pt/nacional/autoridade-maritima-alerta-banhistas-proibido-fazer-isto-quando-bandeira-amarela-praia-multas-podem-ultrapassar-500-euros/"
      ]
    },
    {
      "action": "If unsure what a flag means, ask the lifeguard (banheiro-salvador) on duty rather than guessing from color intuition",
      "success_rate": 0.85,
      "how": "Lifeguards on Portuguese beaches set and enforce the flags directly and can explain current conditions (currents, undertow) that the color alone does not convey.",
      "condition": "Beach has an active lifeguard post",
      "sources": []
    }
  ],
  "workarounds_zh": [],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": [
      "disaster/wildfire-fire-use-ban-critical-period/pt"
    ]
  },
  "official_doc_url": null,
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.75,
  "fix_success_rate": 0.85,
  "resolvable": "true",
  "first_seen": "2026-09-16",
  "last_confirmed": "2026-09-16",
  "last_updated": "2026-09-16",
  "evidence_count": 3,
  "tags": [],
  "locale": "en",
  "aliases": [
    "safety/yellow-flag-swimming-prohibited/pt"
  ]
}