Every moment that you spend enjoying the ocean on the beach or on a rocky shore, your life is in danger. We get used to the rhythm of the waves, which often vary in size within what seem to be predictable limits. However, sometimes the coast is hit by unusually strong, high, powerful waves, that can easily sweep people off the beach or the rocks, or crush them with a driftwood log battering ram. These waves are unpredictable, and can be overwhelmingly powerful.
Every year, more or less, at least one visitor is killed by waves along the Oregon Coast. Thousands of visitors use the area, so it is quite possible to enjoy it and survive, but it's never without risk. You can improve your odds by staying aware of what the waves are doing, and avoiding extra-dangerous spots such as those nearby to logs, or those without a clear and rapid escape path away from the water.
The ocean is a vast reservoir of kinetic energy, easily capable of snatching, crushing, and killing a human being. The next wave may be far larger than the previous hundred were. Please stay aware and stay alive.