Joe wrote:

"One of the tests involves sitting at the chart table, with the ports blacked
out, and predicting your position to within a few metres.

In other words, you have to sail (and navigate) the boat "blind".

No external imput at all.

How can this be done?

Joe
MSV RedCloud

Joe you seem to be rather thick, you must take this post in the context of the
others that preceded it. If you do so you will be aware that there is in fact
"external" input; The examiner is going to tell you your starting position, compass
heading and any course changes, most likely you will also get the boat speed through
the water. You have to plot your course accounting for set, leeway (you are going to
have to know your boats characteristics for this based on angle of heel, something you
can sense in the cabin and therefore another input), drift...., you will have a watch and tide
tables.

To accomplish this with some accuracy is not that difficult, I'm not sure
why you seem to be so astounded by such an ability.

Cheers
Marty