Can someone educate me a bit? Why are long period swells more likely to close out and be unrideable than short period swells? I can see why the size of the wave in relation to the depth and shape of the sandbar would make a wave a wave unrideable, but it's not clear to me why the period (which i understand to mean the period of time between swells) would cause a different result. Someone help out a rookie wave scientist here.