HYDRO – hydrostatics and intact stability program

Hydro now includes a powerful feature that greatly enhances its usefulness to designers and others needing to analyze the hydrostatics of vessels. With version 5.0.19, you have the freedom to specify a vessel’s center of gravity to be positioned anywhere using all three dimensions. You are no longer limited to having the CG located on the vessel’s centerline. When specifying an off-center CG, Hydro will automatically equilibrate the vessel to the correct equilibrium heel angle. In addition, Hydro can calculate the stability curve for a vessel whose CG is off-center for any range of heel angles. To complement this feature, Hydro also allows you to investigate the effect on stability of adding weight at any off-center position. With these new capabilities, Hydro will give you greater flexibility in analyzing a vessel’s stability.

Feel free to sign up for an evaluation version of MultiSurf which includes Hydro.

Download a pdf file detailing the Hydro features.

Hydro is a Windows-based PC program for calculation of flotation and righting moments of an elongated floating body, such as the hull of a boat or a ship. The applications include:

  • evaluations of initial and ultimate stability and flotation, and of heel angles for capsizing and downflooding
  • assessment of effects of design alterations on the above properties
  • determination of sail-carrying ability (for sailing vessels), of tank volumes and ullage curves, of ballast volume and center of gravity, and of hull structural weights and centroids
  • simulation of stability tests for Coast Guard inspection or ocean racing qualification

The Windows-based version of Hydro includes all features of our older, time-tested DOS-version with its interactive interface, screen displays of boat’s attitude and of summary graphs, the option to save and/or print all the results, and easy escape from any calculation.

  • Fixed position hydrostatics — The model can be placed in the water in any position and orientation, the program calculates all the integral quantities of interest to the naval architect:
  • section areas
  • girths
  • displaced volume
  • center of buoyancy
  • waterplane area
  • center of flotation
  • wetted surface
  • righting moments
  • Equilibrated hydrostatics — An automatic balancing algorithm will bring the model into a position of hydrostatic equilibrium under whatever conditions of heel and loading are specified — trim can be specified to equilibrate automatically or to stay fixed.
  • Graphs — The program generates the data needed to plot stability curves and curves of form, righting moment curves, and section area curve. Bonjean curves and dynamic stability calculations are included.
  • Any units (English, metric, or other) — The program works in sea water or fresh water or a liquid of any other density.
  • Critical points — You can name and key in the coordinates of up to 6 specific points whose heights above or below the waterplane will be displayed and/or printed in the standard output summary.

Comprehensive documentation included.

A demo of the program operation.

Price: See Pricelist