We are frequently approached by boat owners or operators whose vessels are exhibiting scary and dangerous behaviors characteristic of 'dynamic instability.' The most frequent causes are related to one or a combination of the following circumstances; the longitudinal center of gravity (LCG) is too far forward for the shape of the wetted portion of the hull lines, the weight of the hull is greater than the wetted dimensions of the hull lines can consistently and adequately support and/or the rudders are ventilating which can lift the stern of the boat. If you know some primary particulars about your boat, you can download and run this dynamic stability calculator.