Scharnhorst's bow suited a different operating area

Did a calculation error cause the Scharnhorst class's poor forward seakeeping?

The design was optimized for the Baltic and North Sea rather than the harsher Atlantic, which is why the ships later received Atlantic bows.

Scharnhorst's poor forward seakeeping is attributed to the waters assumed in the original design. The Baltic and North Sea were the initial focus. Wider raiding plans then required a bow that could cope with the harsher North and South Atlantic. The later Atlantic bow is explained as an adaptation to that expanded operating area.