How is sternway checked when using a sea anchor in heavy surf?

When using a sea anchor in heavy surf, slacking the trip line is essential for checking sternway, which refers to the reverse movement of a vessel due to forces acting upon it, such as waves and wind. When the trip line is slackened, it allows the sea anchor to reposition itself relative to the water's movement and the vessel's motion. This adjustment can help ensure that the sea anchor is properly deployed and effectively catching the water to counteract the sternway.

Sternway might increase if the sea anchor is overly tight, as it can become ineffective if it's not allowed some freedom of movement. By slacking the trip line, the sea anchor can better adapt to the changing conditions of the surf, allowing the vessel to stabilize more effectively.

While tightening the trip line can limit the sea anchor's effectiveness, pulling it or adjusting the holding line does not directly relate to managing the sternway caused by heavy surf conditions.