After a long swim (and beat down), you will be very tempted to stand up when you get close to shore. Think before you stand. If the water is moving quickly and deeper than your knees, you could slip and fall. Worse yet, unstable footing can lead to foot entrapment. Wait for still water like an eddy. Always take your time standing and make certain you have decent footing. Here is a decent video on the subject: When to Stand.