Speed reduction for a given delivered power when a ship enters shallow water - Schlichting’s 1934 correction.
Formula
$$ \frac{V_\text{shallow}}{V_\text{deep}} \approx \tanh\sqrt{h/8T} \quad (h/T < 8) $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $V_\text{deep}$ | Deep-water speed at rated power | kn | sea trial |
| $V_\text{shallow}$ | Shallow-water speed at same power | kn | result |
| $h$ | Water depth | m | chart |
| $T$ | Draft | m | hydrostatics |
Sources
- Schlichting (1934).
- ITTC 7.5-04-01 Shallow Water.