Description
Average nonnegative forward and aft drafts for meanDraft and subtract forward from aft for trim.
Vessel draft, loading moments, and free-surface terms describe different parts of hydrostatic behavior. Their signs, reference positions, and dimensional bases must be stated before comparison.
Average nonnegative forward and aft drafts for meanDraft and subtract forward from aft for trim.
When to use this tool
Use Nautical Draft Forward Aft Average when you need a supplied trim, loading, or hydrostatic component.
How to use the tool and how it works
- Enter forward, aft. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read meanDraft, trim. Use the output convention below.
Average nonnegative forward and aft drafts for meanDraft and subtract forward from aft for trim.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| forward | Forward | Required. Finite number; minimum 0. |
| aft | Aft | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| meanDraft | Mean Draft | Required. Finite number. |
| trim | Trim | Required. Finite number. |
{
"input": {
"forward": 6,
"aft": 8
},
"output": {
"meanDraft": 7,
"trim": 2
}
}Limitations and assumptions
- This arithmetic mean does not account for hull shape, hogging, sagging, or a vessel-specific displacement table.
- 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
Consult vessel-specific hydrostatic and stability information under the relevant loading condition for a complete assessment.
References
Similar or alternative tools
- Vessel Trim Reference Midpoint
Use the slope (aftDraft - forwardDraft) / (aftPosition - forwardPosition) to evaluate draft at referencePosition.
- Vessel Trim Longitudinal Slope Factor
Divide aftDraft minus forwardDraft by positive length for a signed slope.