Added resistance in waves knowing yacht’s radius of gyration (calculation)

Calculation template

How does it work?

The calculation requires LWL, Tc, BWL, c, CP, the yacht’s radius of gyration, Kyy, as well as the significant wave height, H1/3, and the modal period of the sea spectrum, T0.

The sea state is modeled by either the Bretschneider (open sea) or JONSWAP (limited fetch) spectra, considering the yacht is sailing in deep water. A custom value of the water density (default is 1026 kg/m3) can also be provided.

The results are calculated for all combinations of:

  • Froude numbers 0.20, 0.25, 0.30, 0.35, 0.40 and 0.45;
  • Angle of wave incidence, μ, 100, 120, 140, 160, and 180 degrees;
  • Radii of gyration , Kyy, 0.20, 0.25, 0.30 times LWL, and the specific radius of gyration provided;
  • Wavelength/ship length ratio, λ / LWL, starting at 0.5, 0.6 till 4.0
Do you want to read more articles like this?


Some of the links shown below are affiliate links and we may earn a commission at no additional cost to you:



Go to Courses


Go to Merch

Send us a Message