When navigating along a coastline with only a single prominent landmark visible, how does a navigator obtain a 'running fix' (demora y distancia navegada con traslado de línea de posición)?

1. Take an initial bearing to the landmark, record the time and log reading, advance the initial bearing line parallel along the course and distance run, and intersect it with a second bearing to the same landmark
2. Measure the water depth twice and take the average of the two soundings
3. Maintain a constant engine RPM and multiply the GPS speed by the water temperature
4. Steer directly toward the landmark until its vertical angle doubles, then reverse course