Plan shoreline work confidently with realistic breaker estimates for crews daily reports. Choose a method, adjust water level, set margins, and document outcomes fast.
| Scenario | h (m) | T (s) | γ | Water level (m) | Method | Hb (m) | Design (SF=1.10) |
|---|---|---|---|---|---|---|---|
| Shallow foreshore | 1.50 | 6.0 | 0.78 | 0.10 | Depth-limited | 1.248 | 1.373 |
| Moderate depth | 3.00 | 8.0 | 0.80 | 0.00 | Miche | ~2.10 | ~2.31 |
| Lower water level | 2.20 | 7.0 | 0.75 | -0.20 | Depth-limited | 1.500 | 1.650 |
Values are illustrative for training and planning discussions.
Breaking wave height influences runup, splash, and impact loads on temporary works, access routes, cofferdams, and shoreline protection. A conservative breaker estimate helps set safe work windows and size barriers before tides and weather tighten schedules.
For depth-limited breaking, many projects start with a breaker index γ near 0.78. Field and laboratory studies often show practical ranges of roughly 0.70–0.90 depending on beach slope, wave shape, and breaking type. Using γ toward the upper end increases conservatism for temporary works.
Depth at the breaker line is rarely constant during construction. Add a water level adjustment to reflect tide stage, surge, or drawdown. For example, a +0.30 m tide can raise effective depth and increase the depth-limited breaker estimate by about 0.23 m when γ = 0.78.
The Miche criterion links maximum steepness to depth through tanh(2πh/L). It is helpful when you want a physics-based limit using the local wavelength. In moderate depth, it can produce similar values to the depth-limited method, while in deeper conditions it trends toward a steepness ceiling.
Wave period affects wavelength and celerity. Longer periods increase wavelength, which can shift the Miche estimate and change how quickly waves propagate into the work zone. When available, use representative or significant period from forecasts or buoy data, and keep units consistent across inputs.
Construction planning commonly applies a design multiplier to cover uncertainty, setup variability, and forecast error. A simple safety factor between 1.10 and 1.30 is often used for temporary works screening, while final design checks may follow project-specific standards and detailed wave transformation analyses.
Wave steepness H/L provides a quick plausibility check. Values above about 0.10 can indicate very steep conditions or mismatched inputs. Use the notes section to flag shallow depths, unusually high steepness, or periods that do not match the observed sea state.
Start each shift by entering updated depth and water level, then compute a breaker estimate for the expected period. Apply the agreed safety factor and export a PDF for the daily report. If conditions change, rerun and attach the new record to work controls.
Use depth-limited when you have reliable breaking-zone depth and need fast screening. Use Miche when you want a wavelength-based limit using the period. Many teams compute both and adopt the more conservative value for planning.
γ relates breaking height to water depth at breaking. It captures how waves reach a limiting height in shallow water. A common starting value is 0.78, but local slope, breaking type, and wave irregularity can shift it.
Choose a factor based on uncertainty in depth, tide stage, and forecast accuracy. For temporary works screening, 1.10–1.30 is a practical range. Use project requirements or engineering review for final, high-consequence decisions.
It accounts for tides, surge, seasonal levels, or drawdown that change the effective depth. Positive values increase effective depth; negative values reduce it. Update it per shift so the calculator reflects the current site condition.
Period controls wavelength through dispersion. In the Miche method, wavelength directly influences the breaking limit. Period also affects celerity, which matters for how waves arrive and how quickly conditions can change near the work area.
This tool is best for construction planning, temporary works, and quick checks. Detailed seawall or breakwater design typically requires spectral wave data, transformation modeling, water levels, and load methods tailored to the structure and code guidance.
Estimate depth from surveys, bathymetry, or observed breaker location during similar tides. If uncertainty is high, use a conservative depth range, run multiple cases, and apply a higher safety factor. Document assumptions in the exported report.
Use results with engineering judgement and local guidance.
Safer designs start with careful inputs and documentation.
Measure carefully, then build smarter coastal protections today always
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.