I know it doesn't sound bushcrafty or even manly however umbrellas have their uses. When the sun is blazing and you've got some where you got to get having a shield is a godsend. Rain storms without too much wind are nicer under something especially if it turns too hail. While hunting it can hide your shape and camouflage your presents. It can add to your tent, or other sleeping arrangement. It can be used as a walking stick (if long enough) Some umbrella are actually a defensive weapon. How else might tone be put to practical use in the woods?