Video duration: 9:48Video has closed captioning.
One minute the beach is dry. The next, a surprise wave has doused people walking on it. Scientists know little about sneaker waves though the National Weather Service has found they happen more often when the tide is coming in. The waves can be especially dangerous. A coastal safety marker at Smelt Sands State Park near Yachats tells of two boys from Eugene who were swept off a rock and drowned.