The following are a series of stress calculations for a typical attachment (skeg/keel) on a metal boat. The loads represent light loading conditions, and are not meant to represent any specific skeg/keel. Rather, these examples are meant as a generic guide to what happens under various attachment strategies.

Each analysis is comprised of two pictures and a scale. The picture on the left is an exterior view, the picture on the right an interior view. The angle of each view is chosen to show the area of maximum stress. The scale in the middle, as well as the colors are relative to each set of pictures. You cannot compare the colors from one drawing to the colors of the next. You must compare the scale.

The initial load is 1000 PSI in all cases. These drawings serve to show the stress risers that result, and how keel and skeg attachments can be engineered to minimize and eliminate stress risers.