Hi J-P,

there is a German book, "Embleme, Wappen, Malings deutscher U-Boote 1939 - 1945" by Georg Hogel,ISBN 3-7822-0407-7, published in '87 by Koehlers, showing on p. 163 three different emblems for U592, one showing a sort of castle, being the ' Hamburger Wappen' and also a ' Hummel' (wouldn't know the translation for this, looks like a man carrying two (milk ?) buckets). In addition, the text " Arzt vom Dienst NORDATLANTIK Sprechstunde tags u. nachts bis Seegang 5 " was carried a while.

Hope this answers your question.

gH.