Double vague
Jut got back from 4 days of surfing with 6 students. Although we live next to the sea there are no (surf-able) waves in the fjord since it is too sheltered and anyway doesn't have a lot of beaches, glaciers preferring to carve out steep valleys. The trip is part of what we call PBL week which stands for project based learning. The idea is that the students learn something in a different way to the normal classroom routine. It's all part of the CAS programme, surfing being firmly in the Active part. Whilst being bashed about on a particularly wild day I noticed some interesting wave phenomena. One was something called clapotis which I have just discovered means standing wave. This is when the wave reflects back and is superposed onto the incoming wave to create a doubling of amplitude. At one point all the students were in a line paddling for the same wave and suddenly got thrown into the air by the reflected wave. Another phenomenon was the double wave, I don't think there is a French term for this one but according to google translate it would be "double vague". The effect was quite annoying actually because double waves are very difficult (I won't say impossible) to surf. I'm not sure what they are caused by but it might be when there are two swells causing the waves.