a person or thing that excavates. 2. a power-driven machine for digging, moving, or transporting loose gravel, sand, or soil. 3. a sharp, spoonlike instrument used for scraping out diseased tissue, as in dentistry. Origin of excavator. 1805-1815.
If it is a permanent tattoo, then it would last on the bottom of your toe forever. If it's a temporary tattoo, it would probably only last a day or two.
*coughsunscreencough*. Tattoo quality can last anywhere from five years to fifteen but all of them eventually need touching up, it's a fact of life. I don't think it particularly matters whether it's colored in or not, as long as you get a good artist who can crisp it up again when necessary.