Manoeuvring Data - Water Conditions / Speed

Water Depth

The water depth option is only applicable to Merchant vessels, since the calculations are always performed in deep water for Naval vessels.

If shallow water has been selected, then the water depth from the calm water line must be entered in the required input units.

Note:
The water depth edit control is only enabled when shallow water is selected, since the depth is not applicable to deep water.

Approach Speed

The vessel approach speed must be entered and is used in all of the manoeuvring calculations.

The manoeuvring calculations are based on mathematical models derived from regression analysis of data sets of manoeuvring characteristics. As such, the input data should not fall outside the bounds of this regression data. Therefore, there is a limit on the speed used for the calculations.

Since different data sets were used for the analysis of Merchant and Naval vessels, two different speed ranges apply:

For speeds below these maximums, default Hydrodynamic Coefficients can be used (see Manoeuvring Data - Hydrodynamic Derivatives).

If higher speeds are required, then this is allowed, but you cannot use default Hydrodynamic coefficients, as these will fall outside the range of the regression analysis. User defined values should be used.