What is the primary purpose of using a sea anchor?

The primary purpose of using a sea anchor is to stabilize a vessel in rough seas. A sea anchor, which is also known as a drogue, is deployed into the water to create drag. This drag helps to keep the bow of the vessel into the waves, reducing engine strain and preventing the vessel from being tossed around uneasily, which can lead to capsizing or other dangerous conditions. By providing stability, the sea anchor allows the crew to manage the vessel more effectively during periods of rough weather, maintaining control and enhancing safety.

In contrast, increasing speed or improving maneuverability are not functions of a sea anchor. Similarly, while a sea anchor helps in stabilizing, securing a traditional anchor, which is intended to hold a vessel in place on the seabed, is a different function altogether. Thus, the primary role of a sea anchor is specifically to mitigate the effects of heavy seas and maintain stability, which is why this choice is the most accurate.