section 443(2)


443(2) A land surveyor does not commit an offence under subsection (1) where, in his operations as a land surveyor, (a) he takes up, when necessary, a boundary mark mentioned in paragraph (1)(b) and carefully replaces it as it was before he took it up; or (b) he takes up a boundary mark mentioned in paragraph (1)(b) in the course of surveying for a highway or other work that, when completed, will make it impossible or impracticable for that boundary mark to occupy its original position, and he establishes a permanent record of the original position sufficient to permit that position to be ascertained.