Disturbing reflections

In the last couple of days we have twice been sailing on water that seemed invisible! Very disturbing for the helmsperson! The first time was in a 5 km tunnel. We were the only boat travelling through at that time (a luxury) so the surface of the water was like glass and the reflection in the water of the roof of the tunnel was perfect. This had the effect of making the surface of the water disappear! We seemed to be suspended in mid-air with the reflection of the vaulted roof appearing like a yawning cavity underneath us. Driving a boat through a very long and narrow tunnel for nearly an hour takes a lot of concentration. J found the reflection fascinating but also very disconcerting. She had to keep her eyes focussed on the left hand side on the point where a certain part of the boat intersected with a railing on the tunnel. To do otherwise had a very unsettling effect and adversly affected steering accuracy.

The same effect occurred when we left quite early one morning and were sailing along a very calm canal. The surface was like a mirror and the avenue of trees was perfectly reflected in such a way as to make the surface of the water seem to disappear: a very weird experience. C tried to capture these effects with the camera  - see below - but the results not quite as graphic as what we were seeing.