Summer time is basically pool time if you have kids- amirite? and yes, I am that annoying mom at the pool photographing my kids having fun! And they are having fun, wanna know how? The trick is to STOP TELLING YOUR KIDS TO SMILE AT YOU as they're playing in the water and just document the time spent there. Sometimes they might smile at you themselves, and it'll be GENUINE, not the fake "cheese" smile. But shooting in full sun can get tricky, some photographers even avoid it all together but there's really no need for the avoidance. If you know how to balance out your settings in camera, it'll be a fun (if not blinding) experience.
In the above photo, this was taken in full sun. You can try to counter that brightness by letting your camera choose the settings OR by switching to manual mode and turning your shutter speed up pretty far to capture movement well and to have the shutter move faster so that light doesn't have as much time to enter the camera. Your aperture should also be turned up to a higher number, which also closes up more and puts more into focus. Your ISO should be as low a number as it'll go. An example on a place to start is a shutter speed of 1/1250, f stop 5, ISO 100. If this is still too bright, try making your shutter speed even faster or your f stop higher. I've been known to max out my shutter speed even. It also helps to be on continuous mode to help focus on fast movement. If you've played with these settings and it's still too bright? move your EV down at least one stop so -1. For speed, it can also help to look through your eye piece rather than use your live view screen. They focus differently so using your eyepiece is actually way faster. If you find yourself feeling frustrated in manual mode, snap a few in auto, there's nothing wrong with it.
Consider your perspective also. The first photo is shown as pointing down at my daughter, showing the water around her as she sits on the edge. I'm also closer to her, filling the frame more to block out other swimmers and to make it easier to see that little smile. The second photo I'm lower to the ground, changing my perspective to see the bottom of her feet as it prepares to break the surface of the water. Ask yourself "What do I want to remember from this moment?" when framing your shot. One well thought out photo is better than one hundred photos randomly taken.
Using negative space and showing what's all around you can help you show that it's the perfect day for a swim and to tease others that you go the pool all to yourself, as shown above ;) So sometimes stepping away from your subject and capturing the entire scene can also add to the story of your pool day. As mentioned before, it depends on what your goal is for telling the story and remembering the moment.
Get even closer than before for those detail shots. My kids find their wrinkly toes and fingers hilarious so her little feet aids in our story. Another option would have been to shoot from the bottom of the feet to include her body in the shot and her face even, especially if she happened to be laughing at her toes. A smaller aperture such as f 1.8 or 2.8 will blur the surroundings, bringing the attention to the spot you intend. Sometimes in full sun it's hard to balance this out though with a smaller number. If you feel you need to use those higher numbers, feel free!
And be ready for that genuine smile as they actually look at you because you never actually know when this could happen! Well, unless you hear "mom, watch this!" half a million times...which is likely ;) This is another time when using the eye piece can be useful for quick focusing.
What are some tricks you like to use to capture your kids at the pool?