The reports I read said they were thirty feet or more. They get bigger as the depth gets shallower. It may only be six feet (I'd say bigger,however) in the first picture and still raise to 30 feet as it came onshore.
One way to estimate the height is to take the guy's height in the 3rd pix, assume he is 6 feet, and compare that length to the wave. agreed that the wave is further away and therefore smaller in the picture, it still is 2.5 times the height of the man. That makes the waves AT LEAST 15 feet, and I'm betting double that.