Logs on the beach are wet and extremely heavy. It takes only a few inches of water to float a 5 ton log!
A single wave can lift and roll heavy logs, leaving anyone standing, sitting, or kneeling on them to be thrown off and potentially pinned underneath. Even small logs can prove dangerous, as they can be waterlogged and weigh several hundred pounds.
If you see a log in the surf or on the wet sand, STAY OFF OF IT!
Be aware of the surf if sitting on logs higher up on the beach. Sneaker waves can rush up the beach and easily move even the biggest of logs (remember that is how they got there in the first place).