Improper coat

Brown curly improper coat

Black wavy improper coat

A heritable hair coat issue in Portuguese Water Dogs is "improper coat".
Portuguese Water Dogs with improper coat do not have the coat described in the breed standard.
A wavy "improperly coated" PWD will tend to look like a Flat Coated Retriever or Border Collie. A curly "improperly coated" PWD will tend to look like an American Water Spaniel or Curly Coated Retriever.
It is also possible for "improperly coated" dogs to have some undercoat and possibly shed. This condition is one of appearance.

Since March 2010 it's possible to DNA test dogs to find out their Genotype for Improper Coat :-)
Click here for more information about the genetest.

Below you can see the difference between normal(left) and improper(right) coated PWD puppies when growing up

Brown curly puppy
Black wavy puppy