We construct some new
geometrical examples of unimbeddable nets N of order p2 with p an odd prime. The
deficiency of N is p−j where either j = 0 or j = 1. In particular, the examples show
that a bound of Bruck is best possible for nets of order 9,25. Our proof also shows
that deriving a translation plane of order p2 is equivalent to reversing a regulus in the
corresponding spread.