How do I determine where my boats center of gravity is?

When placing your boat on a FLOE boat lift it is important that the center of gravity is centered on the lift cradle to avoid overloading one of the lifting beams.  An easy way to find the center of gravity is to look at how your boat is positioned on the trailer.  The center of gravity would be just inches ahead of the axle because the trailer needs some tongue weight to tow properly.  If you have tandem axles the center of gravity is just in front of the center gap between the two axles.  On a triple axle the mark is just ahead of the center axle.  It is important to note that this is only true if your trailer is set up correctly.  You also need to pay attention to additional weight like fuel, batteries, and gear.  Think of the axle(s) as the fulcrum point.  Zero tongue weight would put the center of gravity directly over the axle(s).