For poolside/night shooting, treat it like any low-light event but use the water creatively. Reflections can be a big asset: include lights or architecture mirrored in the water, and try very low angles near water level for more dramatic portraits—especially if there’s underwater lighting.

For action and candid moments, use a higher ISO and a wide aperture to keep shutter speeds reasonably fast. You may not need extremely fast shutters for splashes, but enough speed to keep people sharp is helpful.

Lighting matters a lot. Avoid direct frontal or overhead light if possible, since it can look harsh and create distracting reflections. Side light or backlight is often more flattering, provided it’s placed high enough to control glare on the water. If you add light, use it sparingly so you don’t overpower the architecture; controlling spill with modifiers like a softbox, reflector, or snoot can help.

Meter carefully—spot metering on faces and bodies is a good approach, since the surrounding water often falls into place naturally.

And above all: keep your gear dry, including any power cords or lighting cables.