Preheat oven to 375°. In a large bowl, whisk flours and salt. Gradually add water and 1/4 cup oil, tossing with a fork until dough holds together when pressed. Divide dough into 3 portions.
On a lightly floured surface, roll each portion of dough to 1/8-in. thickness. Cut with a floured 1-1/2-in. round cookie cutter. Place 1 in. apart on ungreased baking sheets. Prick each cracker with a fork; brush lightly with remaining oil. Mix thyme and sea salt; sprinkle over crackers.
Bake 9-11 minutes or until bottoms are lightly browned.