Which navigation method relies on speed, heading, and time to estimate a vessel's position?

Which navigation method relies on speed, heading, and time to estimate a vessel's position?

• A. Celestial navigation
• B. Dead reckoning
• C. GPS-based navigation
• D. Loran-C navigation

Answer: (B)

Dead reckoning estimates where the vessel is by projecting from a known position using speed through the water, heading, and elapsed time. You take the distance traveled by multiplying speed by time and then plot that distance along the course you’re steering. Repeating this from the last known fix lets you draw a continuous path and maintain a running position estimate. It’s a straightforward, signal-free method, but it carries drift over time because small errors in speed, heading, or unaccounted currents accumulate, so the position slowly drifts from reality unless you periodically check with another navigation method. Celestial navigation uses star or sun observations to compute position, GPS-based navigation uses satellite signals for precise coordinates, and Loran-C uses timing differences from fixed transmitters to triangulate your location.

Dead reckoning estimates where the vessel is by projecting from a known position using speed through the water, heading, and elapsed time. You take the distance traveled by multiplying speed by time and then plot that distance along the course you’re steering. Repeating this from the last known fix lets you draw a continuous path and maintain a running position estimate. It’s a straightforward, signal-free method, but it carries drift over time because small errors in speed, heading, or unaccounted currents accumulate, so the position slowly drifts from reality unless you periodically check with another navigation method. Celestial navigation uses star or sun observations to compute position, GPS-based navigation uses satellite signals for precise coordinates, and Loran-C uses timing differences from fixed transmitters to triangulate your location.