When you get closer to buying . . .
boater's world sells the 2100 for $149.99 + free shipping!!!
http://www.boatersworld.com/webapp/w...ductId=8256714
I didn't have to calibrate my gauge . . . It was right on out of the box. Navman gaurantee's within 5% accuracy out of the box, but it's a good idea to calibrate it anyway . . .