Description
Add transducerBelowSurface to sounding for waterDepth, then subtract draft for underKeel.
A clearance margin compares available vertical space with occupied space and any explicit allowance. Depths, water levels, and structure elevations must share compatible datums.
Add transducerBelowSurface to sounding for waterDepth, then subtract draft for underKeel.
When to use this tool
Use Nautical Sounding Keel Datum Shift when you need a transparent component of a vertical clearance calculation.
How to use the tool and how it works
- Enter sounding, transducerBelowSurface, draft. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read waterDepth, underKeel. Use the output convention below.
Add transducerBelowSurface to sounding for waterDepth, then subtract draft for underKeel.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| sounding | Sounding | Required. Finite number; minimum 0. |
| transducerBelowSurface | Transducer Below Surface | Required. Finite number; minimum 0. |
| draft | Draft | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| waterDepth | Water Depth | Required. Finite number. |
| underKeel | Under Keel | Required. Finite number. |
{
"input": {
"sounding": 10,
"transducerBelowSurface": 2,
"draft": 5
},
"output": {
"waterDepth": 12,
"underKeel": 7
}
}Limitations and assumptions
- All three nonnegative lengths must refer to compatible positions; tide, squat, vessel motion, and survey uncertainty are omitted.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use current surveys, water levels, vessel data, and approved operational margins for an actual passage decision.
References
Similar or alternative tools
- Underkeel Allowance Explicit Components
Add chartedDepth and tideHeight, subtract draft and squat for clearance, then subtract reserve for margin.
- Vessel Airdraft Bridge Datum Gap
Subtract waterElevation from bridgeElevation for availableClearance, then subtract nonnegative airDraft for margin.