In high latitudes, celestial observations can be made over a horizon covered with pack ice by bringing the sun tangent to the ice and __________.

Correct Answer: Option C — using a dip correction based on the height of eye above the ice

When navigating in high latitudes over pack ice, the apparent sea horizon is elevated by the ice surface. Navigators must apply a dip correction based specifically on the observer's height of eye above the ice pack rather than standard sea-level tables, per Bowditch.