Devices, systems, and methods may be used for wirelessly communicating underwater (or through air) with equipment such as, but not necessarily limited to, automatic swimming pool cleaners (APCs). Such communication avoids any need for conventional wired communication with the APCs. At least some of the devices may be hand-held and capable of having at least portions immersed in water in normal use. The devices preferably do not use radio frequency (RF) signal to communication with APCs, instead employing light-based or other signal types.