{"abstract":"At high water the anchor has too little scope and drags.","category":"Tide and marine navigation tables","checks":7,"contract":"Input [depth, tmax, tmin, bow, scope, boat_len]: charted depth and tide heights above datum (m). Rode = scope*(depth+tmax+bow) rounded up to the next 5 m chain mark. Swing radius = sqrt(rode^2 - (depth+tmin+bow)^2) + boat_len (largest at the lowest tide), rounded to 0.1 m. Return [rode, radius].","contract_signature":"x","evaluation_group":"w2-tide_and_marine_navigation_tables-anchoring","failed_approach":"Using the mean of high and low tide still leaves short scope at high water.","family":"w2-tide_and_marine_navigation_tables-anchoring-design-tide","id":"FA-69316","implementations":{"attempt":{"sha256":"a481348b2890eb60ebc84c403a15bbfc78dd202783fb0f7910aa54f2ce7a7ff1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(x):\n    d,tmax,tmin,bow,scope,blen=x\n    L=scope*(d+(tmax+tmin)/2+bow)\n    L=math.ceil(L/5-1e-9)*5\n    v=d+tmin+bow\n    r=math.sqrt(L*L-v*v)+blen\n    return [L,round(r,1)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 5, 11]', [4.0, 3.2, 0.6, 1.2, 5, 11], [45, 55.6]), ('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]', [4.0, 3.2, 0.6, 1.2, 4, 11], [35, 45.5]), ('anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]', [8.0, 5.1, 0.3, 1.5, 3, 14], [45, 57.9]), ('anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]', [2.5, 1.0, 0.2, 1.0, 7, 9], [35, 43.8]), ('anchor rode and swing radius [4.2, 1.4, 0.4, 1.4, 5, 10]', [4.2, 1.4, 0.4, 1.4, 5, 10], [35, 44.5]), ('anchor rode and swing radius [6.0, 2.0, 2.0, 1.0, 5, 12]', [6.0, 2.0, 2.0, 1.0, 5, 12], [45, 56.1]), ('anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]', [3.0, 4.0, 1.0, 1.5, 5, 8], [45, 52.7])], [('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]', [4.0, 3.2, 0.6, 1.2, 4, 11], [35, 45.5]), ('anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]', [2.5, 1.0, 0.2, 1.0, 7, 9], [35, 43.8]), ('anchor rode and swing radius [4.2, 1.4, 0.4, 1.4, 5, 10]', [4.2, 1.4, 0.4, 1.4, 5, 10], [35, 44.5]), ('anchor rode and swing radius [6.0, 2.0, 2.0, 1.0, 5, 12]', [6.0, 2.0, 2.0, 1.0, 5, 12], [45, 56.1]), ('anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]', [3.0, 4.0, 1.0, 1.5, 5, 8], [45, 52.7]), ('anchor rode and swing radius [10.0, 0.5, 0.1, 2.0, 4, 20]', [10.0, 0.5, 0.1, 2.0, 4, 20], [50, 68.5]), ('anchor rode and swing radius [5.0, 1.0, 0.5, 1.0, 6, 10]', [5.0, 1.0, 0.5, 1.0, 6, 10], [45, 54.5])], [('anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]', [8.0, 5.1, 0.3, 1.5, 3, 14], [45, 57.9]), ('anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]', [3.0, 4.0, 1.0, 1.5, 5, 8], [45, 52.7]), ('anchor rode and swing radius [10.0, 0.5, 0.1, 2.0, 4, 20]', [10.0, 0.5, 0.1, 2.0, 4, 20], [50, 68.5]), ('anchor rode and swing radius [5.0, 1.0, 0.5, 1.0, 6, 10]', [5.0, 1.0, 0.5, 1.0, 6, 10], [45, 54.5]), ('anchor rode and swing radius [2.0, 0.5, 0.5, 1.0, 7, 7]', [2.0, 0.5, 0.5, 1.0, 7, 7], [25, 31.8]), ('anchor rode and swing radius [4.2, 2.1, 1.0, 1.2, 4, 10]', [4.2, 2.1, 1.0, 1.2, 4, 10], [30, 39.3]), ('anchor rode and swing radius [1.1, 1.3, 0.4, 0.6, 5, 6]', [1.1, 1.3, 0.4, 0.6, 5, 6], [15, 20.9])], [('anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]', [2.5, 1.0, 0.2, 1.0, 7, 9], [35, 43.8]), ('anchor rode and swing radius [2.0, 0.5, 0.5, 1.0, 7, 7]', [2.0, 0.5, 0.5, 1.0, 7, 7], [25, 31.8]), ('anchor rode and swing radius [4.2, 2.1, 1.0, 1.2, 4, 10]', [4.2, 2.1, 1.0, 1.2, 4, 10], [30, 39.3]), ('anchor rode and swing radius [1.1, 1.3, 0.4, 0.6, 5, 6]', [1.1, 1.3, 0.4, 0.6, 5, 6], [15, 20.9]), ('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 5, 11]', [4.0, 3.2, 0.6, 1.2, 5, 11], [45, 55.6]), ('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]', [4.0, 3.2, 0.6, 1.2, 4, 11], [35, 45.5]), ('anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]', [8.0, 5.1, 0.3, 1.5, 3, 14], [45, 57.9])], [('anchor rode and swing radius [4.2, 1.4, 0.4, 1.4, 5, 10]', [4.2, 1.4, 0.4, 1.4, 5, 10], [35, 44.5]), ('anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]', [3.0, 4.0, 1.0, 1.5, 5, 8], [45, 52.7]), ('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 5, 11]', [4.0, 3.2, 0.6, 1.2, 5, 11], [45, 55.6]), ('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]', [4.0, 3.2, 0.6, 1.2, 4, 11], [35, 45.5]), ('anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]', [8.0, 5.1, 0.3, 1.5, 3, 14], [45, 57.9]), ('anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]', [2.5, 1.0, 0.2, 1.0, 7, 9], [35, 43.8]), ('anchor rode and swing radius [6.0, 2.0, 2.0, 1.0, 5, 12]', [6.0, 2.0, 2.0, 1.0, 5, 12], [45, 56.1])]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"706cd6fd5252992efa95a679508b563c38114b5bbe245aa616903cd123fa8412","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(x):\n    d,tmax,tmin,bow,scope,blen=x\n    L=scope*(d+tmin+bow)\n    L=math.ceil(L/5-1e-9)*5\n    v=d+tmin+bow\n    r=math.sqrt(L*L-v*v)+blen\n    return [L,round(r,1)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 5, 11]', [4.0, 3.2, 0.6, 1.2, 5, 11], [45, 55.6]), ('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]', [4.0, 3.2, 0.6, 1.2, 4, 11], [35, 45.5]), ('anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]', [8.0, 5.1, 0.3, 1.5, 3, 14], [45, 57.9]), ('anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]', [2.5, 1.0, 0.2, 1.0, 7, 9], [35, 43.8]), ('anchor rode and swing radius [4.2, 1.4, 0.4, 1.4, 5, 10]', [4.2, 1.4, 0.4, 1.4, 5, 10], [35, 44.5]), ('anchor rode and swing radius [6.0, 2.0, 2.0, 1.0, 5, 12]', [6.0, 2.0, 2.0, 1.0, 5, 12], [45, 56.1]), ('anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]', [3.0, 4.0, 1.0, 1.5, 5, 8], [45, 52.7])], [('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]', [4.0, 3.2, 0.6, 1.2, 4, 11], [35, 45.5]), ('anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]', [2.5, 1.0, 0.2, 1.0, 7, 9], [35, 43.8]), ('anchor rode and swing radius [4.2, 1.4, 0.4, 1.4, 5, 10]', [4.2, 1.4, 0.4, 1.4, 5, 10], [35, 44.5]), ('anchor rode and swing radius [6.0, 2.0, 2.0, 1.0, 5, 12]', [6.0, 2.0, 2.0, 1.0, 5, 12], [45, 56.1]), ('anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]', [3.0, 4.0, 1.0, 1.5, 5, 8], [45, 52.7]), ('anchor rode and swing radius [10.0, 0.5, 0.1, 2.0, 4, 20]', [10.0, 0.5, 0.1, 2.0, 4, 20], [50, 68.5]), ('anchor rode and swing radius [5.0, 1.0, 0.5, 1.0, 6, 10]', [5.0, 1.0, 0.5, 1.0, 6, 10], [45, 54.5])], [('anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]', [8.0, 5.1, 0.3, 1.5, 3, 14], [45, 57.9]), ('anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]', [3.0, 4.0, 1.0, 1.5, 5, 8], [45, 52.7]), ('anchor rode and swing radius [10.0, 0.5, 0.1, 2.0, 4, 20]', [10.0, 0.5, 0.1, 2.0, 4, 20], [50, 68.5]), ('anchor rode and swing radius [5.0, 1.0, 0.5, 1.0, 6, 10]', [5.0, 1.0, 0.5, 1.0, 6, 10], [45, 54.5]), ('anchor rode and swing radius [2.0, 0.5, 0.5, 1.0, 7, 7]', [2.0, 0.5, 0.5, 1.0, 7, 7], [25, 31.8]), ('anchor rode and swing radius [4.2, 2.1, 1.0, 1.2, 4, 10]', [4.2, 2.1, 1.0, 1.2, 4, 10], [30, 39.3]), ('anchor rode and swing radius [1.1, 1.3, 0.4, 0.6, 5, 6]', [1.1, 1.3, 0.4, 0.6, 5, 6], [15, 20.9])], [('anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]', [2.5, 1.0, 0.2, 1.0, 7, 9], [35, 43.8]), ('anchor rode and swing radius [2.0, 0.5, 0.5, 1.0, 7, 7]', [2.0, 0.5, 0.5, 1.0, 7, 7], [25, 31.8]), ('anchor rode and swing radius [4.2, 2.1, 1.0, 1.2, 4, 10]', [4.2, 2.1, 1.0, 1.2, 4, 10], [30, 39.3]), ('anchor rode and swing radius [1.1, 1.3, 0.4, 0.6, 5, 6]', [1.1, 1.3, 0.4, 0.6, 5, 6], [15, 20.9]), ('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 5, 11]', [4.0, 3.2, 0.6, 1.2, 5, 11], [45, 55.6]), ('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]', [4.0, 3.2, 0.6, 1.2, 4, 11], [35, 45.5]), ('anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]', [8.0, 5.1, 0.3, 1.5, 3, 14], [45, 57.9])], [('anchor rode and swing radius [4.2, 1.4, 0.4, 1.4, 5, 10]', [4.2, 1.4, 0.4, 1.4, 5, 10], [35, 44.5]), ('anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]', [3.0, 4.0, 1.0, 1.5, 5, 8], [45, 52.7]), ('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 5, 11]', [4.0, 3.2, 0.6, 1.2, 5, 11], [45, 55.6]), ('anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]', [4.0, 3.2, 0.6, 1.2, 4, 11], [35, 45.5]), ('anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]', [8.0, 5.1, 0.3, 1.5, 3, 14], [45, 57.9]), ('anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]', [2.5, 1.0, 0.2, 1.0, 7, 9], [35, 43.8]), ('anchor rode and swing radius [6.0, 2.0, 2.0, 1.0, 5, 12]', [6.0, 2.0, 2.0, 1.0, 5, 12], [45, 56.1])]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"A deterministic toy model with stipulated rules and constants; not certified hydrographic software or a substitute for official tide tables. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-tide_and_marine_navigation_tables-anchoring-design-tide","generated_at":"2026-09-29T14:48:10.266077+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Tide tables and passage plans turn published predictions into go/no-go decisions about depth, clearance and timing.","root_cause":"Rode length is based on the minimum instead of the maximum tide during the stay.","sha256":"f5d888d9a962249ee2150f455fae0f58e94f79f9e598d989f2c73f1aef25d9b9","title":"Anchor rode and swing radius: Rode length uses the lowest tide · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":41.666,"exit_code":1,"observations":[{"actual":[40,50.6],"check":"anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 5, 11]","expected":[45,55.6],"passed":false},{"actual":[30,40.4],"check":"anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]","expected":[35,45.5],"passed":false},{"actual":[40,52.8],"check":"anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]","expected":[45,57.9],"passed":false},{"actual":[30,38.8],"check":"anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]","expected":[35,43.8],"passed":false},{"actual":[35,44.5],"check":"anchor rode and swing radius [4.2, 1.4, 0.4, 1.4, 5, 10]","expected":[35,44.5],"passed":true},{"actual":[45,56.1],"check":"anchor rode and swing radius [6.0, 2.0, 2.0, 1.0, 5, 12]","expected":[45,56.1],"passed":true},{"actual":[35,42.6],"check":"anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]","expected":[45,52.7],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 5, 11]\", \"actual\": [40, 50.6], \"expected\": [45, 55.6], \"passed\": false}, {\"check\": \"anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]\", \"actual\": [30, 40.4], \"expected\": [35, 45.5], \"passed\": false}, {\"check\": \"anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]\", \"actual\": [40, 52.8], \"expected\": [45, 57.9], \"passed\": false}, {\"check\": \"anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]\", \"actual\": [30, 38.8], \"expected\": [35, 43.8], \"passed\": false}, {\"check\": \"anchor rode and swing radius [4.2, 1.4, 0.4, 1.4, 5, 10]\", \"actual\": [35, 44.5], \"expected\": [35, 44.5], \"passed\": true}, {\"check\": \"anchor rode and swing radius [6.0, 2.0, 2.0, 1.0, 5, 12]\", \"actual\": [45, 56.1], \"expected\": [45, 56.1], \"passed\": true}, {\"check\": \"anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]\", \"actual\": [35, 42.6], \"expected\": [45, 52.7], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.174,"exit_code":1,"observations":[{"actual":[30,40.4],"check":"anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 5, 11]","expected":[45,55.6],"passed":false},{"actual":[25,35.3],"check":"anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]","expected":[35,45.5],"passed":false},{"actual":[30,42.4],"check":"anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]","expected":[45,57.9],"passed":false},{"actual":[30,38.8],"check":"anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]","expected":[35,43.8],"passed":false},{"actual":[30,39.4],"check":"anchor rode and swing radius [4.2, 1.4, 0.4, 1.4, 5, 10]","expected":[35,44.5],"passed":false},{"actual":[45,56.1],"check":"anchor rode and swing radius [6.0, 2.0, 2.0, 1.0, 5, 12]","expected":[45,56.1],"passed":true},{"actual":[30,37.5],"check":"anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]","expected":[45,52.7],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 5, 11]\", \"actual\": [30, 40.4], \"expected\": [45, 55.6], \"passed\": false}, {\"check\": \"anchor rode and swing radius [4.0, 3.2, 0.6, 1.2, 4, 11]\", \"actual\": [25, 35.3], \"expected\": [35, 45.5], \"passed\": false}, {\"check\": \"anchor rode and swing radius [8.0, 5.1, 0.3, 1.5, 3, 14]\", \"actual\": [30, 42.4], \"expected\": [45, 57.9], \"passed\": false}, {\"check\": \"anchor rode and swing radius [2.5, 1.0, 0.2, 1.0, 7, 9]\", \"actual\": [30, 38.8], \"expected\": [35, 43.8], \"passed\": false}, {\"check\": \"anchor rode and swing radius [4.2, 1.4, 0.4, 1.4, 5, 10]\", \"actual\": [30, 39.4], \"expected\": [35, 44.5], \"passed\": false}, {\"check\": \"anchor rode and swing radius [6.0, 2.0, 2.0, 1.0, 5, 12]\", \"actual\": [45, 56.1], \"expected\": [45, 56.1], \"passed\": true}, {\"check\": \"anchor rode and swing radius [3.0, 4.0, 1.0, 1.5, 5, 8]\", \"actual\": [30, 37.5], \"expected\": [45, 52.7], \"passed\": false}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}