Personally I feel comfortable with this: 2.5-3.5" of clear ice to walk around and fish from a lawn chair, 4-6" of clear ice for the wheeler and portable shack, 8" for the big shack and usually 12-14" for the truck (Ranger 4x4).

The biggest mistake made during early season is when someone ASSUMES that the ice thisckness is consistent. 4" can turn into 1" within 10'.

If you're not sure STAY HOME!!!!