{
  "date": "2026-10-16",
  "status": "PASS",
  "requirement": {
    "id": "DRAFT-001",
    "max_draft_m": 0.53,
    "reference": "float hull skin",
    "appendages_included": false,
    "confirmed_by_user": true,
    "supersedes_m": 0.52
  },
  "independent": {
    "draft_m": 0.53,
    "volume_m3": 6.981205026537738,
    "mass_kg": 7155.735152201182,
    "LCB_m": -0.7010496247230684,
    "KB_m": 0.32785918906079736,
    "wetted_area_m2": 34.532497623748476,
    "integral_x2_m5": 58.723986128766164,
    "integral_y2_m5": 66.54123653533777,
    "mass_fresh_kg": 6981.205026537738,
    "increment_vs_052_salt_kg": 211.6363854221554
  },
  "native_ship": {
    "date": "2026-10-16",
    "FreeCAD": [
      "1",
      "1",
      "4",
      "20260928 (Git shallow)",
      "Unknown",
      "2026/09/28 13:46:34",
      "(HEAD detached at 4fd3bf320)",
      "4fd3bf320d9566a27e60069fc8387448aaa3a094"
    ],
    "source_sha256": "2017ed784828a44002d722219b461f099f2ce543aaeb2514e268bc50aad25202",
    "records": [
      {
        "name": "PortHull",
        "solids": 1,
        "closed": true,
        "valid": true,
        "volume_mm3": 25216818888.781033,
        "faces": 19140
      },
      {
        "name": "StarboardHull",
        "solids": 1,
        "closed": true,
        "valid": true,
        "volume_mm3": 25216818888.781033,
        "faces": 19140
      }
    ],
    "both_positive_closed_valid_solids": true,
    "draft_m": 0.53,
    "mass_kg": 7155.735152201414,
    "volume_m3": 6.981205026537965,
    "LCB_m": -0.7010496247231142,
    "KB_m": 0.32785918906080375,
    "waterplane_m2": 20.71415110776115,
    "IT_m4": 197.7164527942308,
    "IL_origin_m4": 224.43555885807945,
    "waterplanes": 2,
    "elapsed_seconds": 39.12946796417236,
    "source_unchanged": true,
    "status": "PASS"
  },
  "relative_errors": {
    "mass_kg": 3.241851231905457e-14,
    "volume_m3": 3.241851231905457e-14,
    "LCB_m": 6.52811138479592e-14,
    "KB_m": 1.942890293094024e-14
  },
  "mass_limits_upright": [
    {
      "density_kg_m3": 1025,
      "mass_kg": 7155.735152201182
    },
    {
      "density_kg_m3": 1000,
      "mass_kg": 6981.205026537738
    }
  ],
  "proposed_working_mass_kg_unchanged": 6500,
  "margin_below_geometric_salt_limit_kg": 655.7351522011822,
  "7200kg_exceeds_salt_limit_by_kg": 44.264847798817755,
  "source_unchanged": true,
  "limitations": [
    "upright geometry only; not an approved safe displacement",
    "actual weights/CG/tanks and local draft with trim/heel pending",
    "skin layup comparison still uses historic 0.52m boundary",
    "PDF v4.0 predates this change"
  ]
}