Source: https://guthlabs.ai/docs/instruments/rip-current-risk-rough-estimator/implementation/

instrument implementation / implementation-contract

# Rip Current Risk Rough Estimator implementation

A source-bound implementation contract for Rip Current Risk Rough Estimator; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t7-123

**Effect**: Computation or source lookup only

## Input and validation requirements

The instrument cannot be evaluated from the supplied specification because its required NOAA-style lookup table, numeric score rules, valid ranges, branch boundaries, and directional convention are missing. Extreme inputs additionally expose the absence of stated clamping or overflow handling.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "wave_height_m": 0.5,
    "wave_period_s": 8,
    "wind_speed_kt": 10,
    "wind_direction_relative_to_shore": "onshore"
  },
  "expected_outputs": {
    "provisional_score": 3,
    "risk_category": "moderate",
    "beaufort_wind_force": 3
  },
  "reference_data": {
    "wave_height_rows": [
      {
        "condition": "0.5 m <= H < 1.0 m",
        "points": 1,
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      },
      {
        "condition": "H < 0.5 m",
        "points": 0,
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      },
      {
        "condition": "H >= 1.0 m",
        "points": 2,
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      }
    ],
    "wave_period_rows": [
      {
        "condition": "8 s <= T < 12 s",
        "points": 1,
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      },
      {
        "condition": "T < 8 s",
        "points": 0,
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      },
      {
        "condition": "T >= 12 s",
        "points": 2,
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      }
    ],
    "wind_rows": [
      {
        "condition": "onshore and wind speed < 15 kt",
        "points": 1,
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      },
      {
        "condition": "onshore and wind speed >= 15 kt",
        "points": 2,
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      },
      {
        "condition": "offshore or alongshore",
        "points": 0,
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      }
    ],
    "risk_cutoffs": [
      {
        "score": "0-2",
        "category": "low",
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      },
      {
        "score": "3-4",
        "category": "moderate",
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      },
      {
        "score": "5-6",
        "category": "high",
        "source_convention": "instrument-defined provisional rubric; not an NOAA standard"
      }
    ],
    "beaufort_entry": {
      "wind_speed_range_kt": "7-10",
      "beaufort_force": 3,
      "description": "gentle breeze",
      "source_convention": "widely tabulated standard Beaufort scale; WMO/International Meteorological Vocabulary convention"
    }
  },
  "working": "Wave contribution: H=0.5 m is exactly on the 0.5 m boundary, so 1 point. Period contribution: T=8 s is exactly on the 8 s boundary, so 1 point. Wind contribution: 10 kt is onshore and below 15 kt, so 1 point. Total = 1 + 1 + 1 = 3. A score of 3 is in the 3-4 moderate band. Independent table check: 10 kt lies in the standard Beaufort-force-3 range of 7-10 kt."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/rip-current-risk-rough-estimator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/rip-current-risk-rough-estimator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/rip-current-risk-rough-estimator/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche7/tranche7-results.json`