Many dive computers have menus, various selectable options and various display modes, which are controlled by a small number of buttons. Control of the computer display differs between manufacturers and in some cases between models by the same manufacturer. The diver may need information not displayed on the default screen during a dive, and the button sequence to access the information may not be immediately obvious. If the diver becomes familiar with the control of the computer on dives where the information is not critical before relying on it for more challenging dives there is less risk of confusion which may lead to an accident.