{
  "slug": "anchor-rode-scope",
  "title": "Anchor Rode & Scope Calculator",
  "heading": "Anchor Rode & Scope Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/anchor-rode-scope",
  "summary": "How much anchor line to let out for a given depth.",
  "description": "Scope is the ratio of rode deployed to the vertical distance from bow roller to seabed. Under 5:1 in wind is how boats drag.",
  "formula": "Rode = (depth + freeboard + tide) × scope ratio.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=anchor-rode-scope",
  "inputs": [
    {
      "id": "depth",
      "label": "Water depth",
      "kind": "number",
      "hint": null,
      "default": 20,
      "unit": "ft",
      "min": 1,
      "max": null
    },
    {
      "id": "freeboard",
      "label": "Bow height above water",
      "kind": "number",
      "hint": null,
      "default": 4,
      "unit": "ft",
      "min": 0,
      "max": null
    },
    {
      "id": "tide",
      "label": "Expected tide rise",
      "kind": "number",
      "hint": null,
      "default": 3,
      "unit": "ft",
      "min": 0,
      "max": null
    },
    {
      "id": "scope",
      "label": "Scope ratio (X:1)",
      "kind": "number",
      "hint": null,
      "default": 7,
      "unit": null,
      "min": 3,
      "max": 12
    }
  ],
  "outputs": [
    {
      "id": "rode",
      "label": "Rode to deploy",
      "format": "decimal",
      "hint": "feet",
      "primary": true
    },
    {
      "id": "height",
      "label": "Total vertical height",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "swing",
      "label": "Approx swing radius (ft)",
      "format": "decimal",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Water depth: 20 ft",
      "Bow height above water: 4 ft",
      "Expected tide rise: 3 ft",
      "Scope ratio (X:1): 7"
    ],
    "outputs": [
      "Rode to deploy: 189",
      "Total vertical height: 27",
      "Approx swing radius (ft): 219"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter water depth (ft).",
      "Enter bow height above water (ft).",
      "Enter expected tide rise (ft).",
      "Enter scope ratio (x:1).",
      "Read your rode to deploy on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "depth": 12,
        "freeboard": 2.4,
        "tide": 1.7999999999999998,
        "scope": 4
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "depth": 20,
        "freeboard": 4,
        "tide": 3,
        "scope": 7
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "depth": 32,
        "freeboard": 6.4,
        "tide": 4.800000000000001,
        "scope": 11
      }
    }
  ],
  "limitations": [
    "Estimates assume standard, average conditions — local rules, pricing, and materials vary.",
    "Results are rounded for readability; add a buffer before ordering, booking, or committing.",
    "Double-check anything with a real cost attached against a local quote."
  ],
  "faq": [
    {
      "q": "How does the anchor rode & scope calculator work?",
      "a": "Scope is the ratio of rode deployed to the vertical distance from bow roller to seabed. Under 5:1 in wind is how boats drag. The underlying maths is: Rode = (depth + freeboard + tide) × scope ratio."
    },
    {
      "q": "What do I need to enter?",
      "a": "4 values: water depth, bow height above water, expected tide rise, and scope ratio (x:1). Each field starts with a sensible default, so you can change one number at a time and watch the result move."
    },
    {
      "q": "What does the rode to deploy result mean?",
      "a": "feet It is returned as a decimal number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds."
    },
    {
      "q": "Is this calculator free, and do I need an account?",
      "a": "Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser."
    },
    {
      "q": "How accurate is the result?",
      "a": "It applies the standard formula exactly, so the arithmetic is precise. Estimates assume standard, average conditions — local rules, pricing, and materials vary."
    },
    {
      "q": "Who is this tool for?",
      "a": "It's built for anyone doing everyday planning maths — a quick estimate that would otherwise need four browser tabs and a calculator app."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/nautical-distance"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Anchor Rode & Scope Calculator (https://www.revenuelab.fyi/toolbox/anchor-rode-scope)"
}