Portuguese Water Dogs have one of two coat types those being either curly or wavy.  Curly coat is described as compact, cylindrical curls somewhat lusterless.  Wavy coat falls gently in waves not curls with slight sheen.  No preference is given to either coat type.  

It also needs to be pointed out that PWD's do shed, but not a lot.  PWD's have a single coat of hair and not fur like most dogs.  Hair unlike fur will continue to grow until you cut it. 

They require routine coat care.  Dogs should be brushed a couple times a week and care should be taken to ensure mats are removed down to the skin. Porties require a full grooming every 6-8 weeks.  Routine ear cleaning is important, especially after swimming.

There are two coat clips, a retriever or lion.  The Lion clip is the traditional breed clip.  It is thought this clip's purpose was to keep the hair long surrounding vital organs thus providing insulation against the cold water. Closely trimming the hair on the hind quarter enables the dog to move their rear legs freely in the water.  

You can find a grooming guide for each clip on the PWDCA website.