Dutch Blue & White Royal Delft Crisis Plate 1931. Keep Heart ! Thankless the gloomy distance, despair not

The center of the tin glazed earthenware plate decorated in shades of blue with a Dutch brown sailing vessel in wavy water. The rim with the text:
HOUDT MOED ! ONDANKS HET DUISTERE VERSCHIET, VERTWIJFEL NIET.
(Keep Heart ! Thankless the gloomy distance, despair not.) 
Signed on the back in underglaze blue for:
DE PORCELEYNE FLES - ROYAL DELFT
DELFT - HOLLAND & BA = 1931              
Painter’s initials:CK = Georg Coenrad Kunz.
Employment dates:  7 Sept. 1891 - 1945.
Literature:
Some crisis plates are shown in Rick Erickson - Royal Delft Page 143 
This plate is only mentioned on page 142.

Diam.:  18 cm.  (7,1 inches.)
Weight:  254 grams