The accessory rail system easily attaches to the Guardian full-face mask and makes it possible to mount various devices to the sides of the mask. Dive lights, video lights, video cameras, sonar, manifold blocks, and welding visors are just a few examples of the equipment that works well with the rail system. Devices are attached to the removable slide and then slide on to the rail. The slide is released from the rail by pressing the release button. The rail stays mounted to the mask, while the devices are attached to slides. The camera, lights and other devices are then changed by simply sliding them on or off the rail. This quick disconnect feature allows surface support to quickly exchange or replace devices as the mission dictates without removing the mask from the diver, or the diver from the water. One rail may be used or two may be mounted (one on each side). The attachment method does not interfere with commonly used surface breathing valve.