The Saucer tool will draw an Arc on the Chart. This Arc is a one half of an Ellipse (or a circle) depending on how it is drawn.
There are many applications for this tool, however the most common is simply as a method of marking up the chart to describe areas of support and resistance.
When using it from the perspective of the Arc tool, you can also see how some markets can unfold over a period of equal time, as displayed in this image.
Usage
Select the button for Saucer Lines from the Toolbar.
Move the mouse pointer over the starting position for the Line. This may be either a high or a low price.
Press the left mouse button, and keeping it pressed down, drag the mouse pointer to the desired end point and release the left mouse button.
Properties
The property editor as well as other functions may be accessed by holding the mouse pointer over the indicator line and Clicking the Right Mouse button. A popup menu will appear (see picture).
The user may then open the Indicator Property Editor, Duplicate the line, move the Line above or below other indicators, hide the Saucer line or delete the Line from the Chart.
Property Editor
The property editor as well as other functions may be accessed by holding the mouse pointer over the indicator line and Clicking the Right Mouse button. You can also access the Property Editor directly by 'Double Clicking' on the line. All the basic drawing tools share the same property editor allowing the user to alter the following properties:
Line Color
Line Width
After alteration, the user has the ability to set these settings as default for all future lines drawn on the page.
The property editor as well as other functions may be accessed by holding the mouse pointer over the indicator line and Clicking the Right Mouse button. A popup menu will appear (see picture). 
The property editor as well as other functions may be accessed by holding the mouse pointer over the indicator line and Clicking the Right Mouse button. You can also access the Property Editor directly by 'Double Clicking' on the line. All the basic drawing tools share the same property editor allowing the user to alter the following properties: