Which one of the following is used to help navigate and determine a vessel's position?

Bearings are used in navigation to determine a vessel's position relative to a reference point. By taking a bearing, a navigator can measure the angle between their current position and a known landmark, buoy, or geographical feature. This method is crucial in triangulating position when combined with other bearings from different points of reference. It allows for accurate plotting on a chart, helping sailors navigate safely.

Digital maps, while useful for representing navigational information, are essentially tools that display data rather than methods for determining position. Wave patterns can provide clues about nearby underwater features or currents but are not a direct means of navigation. Buoy placements indicate navigational routes and hazards but do not give a direct method for calculating a position on their own.