HomeCalculatorsSchlichting Shallow-Water Correction

Schlichting Shallow-Water Correction

Speed reduction for a given delivered power when a ship enters shallow water - Schlichting's 1934 correction.

ResistanceShallow water
Shallow-water speed (same power)
6.83kn
Speed loss
51.2%
Formula, assumptions, and limits

Simplified Schlichting correction valid for h/T < 8. Beyond that, shallow-water losses are negligible. Full Schlichting chart also includes the wave-resistance increment driven by Fn_h = V/√(g·h).

Symbol legend

SymbolMeaningUnitSource
Deep-water speed at rated powerknsea trial
Shallow-water speed at same powerknresult
Water depthmchart
Draftmhydrostatics