The sketch plan shall be required to enable the subdivider to
save time and expense in reaching a general agreement with the Planning
Board as to form, layout and objectives of these subdivision regulations.
Approval of the sketch plan shall expire six months after the
date of such formal action, unless a proper application for a subdivision
has been submitted to the Planning Board. No further Planning Board
action will be taken after such expiration until a new sketch plan
has been submitted or the plan is resubmitted.