'Triangulation' is the art of taking a compass bearing on two fixed objects (landmarks) and finding yourself at their intersecting points.
They followed the stars
Keep clear of stand on boats
keep clear of stand-on boats
keep clear of stand-on boats
keep clear of stand-on boats
Keep clear of stand on boats
Keep clear of stand on boats
Keep clear of stand on boats
keep clear of stand on boats
keep clear of stand on boats
Yes they did to keep enemy boats out.
People used compass to keep people from getting lost.