In navigation, it is always important to be able to locate yourself. Evaluating distances without the need for an electronic device helps you appreciate your route. It's also useful for preventing a collision. Of course, you can corroborate your estimate with a GPS or AIS.
Here are some tips to appreciate these distances.
Stand on the deck of your boat (about 2 m above the water) and look at the coast. Depending on your distance you will be able to appreciate more or less details.
4 miles away
- On land: we recognize the shape of trees and houses. We do not see a beach.
- At sea: We see the superstructure of a big boat and the sailboats are white dots
2 miles away
- On the ground: we can see the doors and windows of the houses, but not yet the people.
- At sea: we can hardly distinguish the big buoys. At night, we start to see the lights of the boats.
At 1 mile
- On the ground: We see the details of the buildings. The people form small black dots.
- At sea: The small buoys and the portholes of the freighters become visible.
At ½ mile
- On the ground: cars can be distinguished. People are visible and we can follow their movements.
- At sea: We can see the crew on the deck and we can distinguish the rigging of a sailing boat.
