Many thanks to SWLing Post reader, Harald Kuhl, who writes:

As in past years, German broadcaster NDR will transmit its domestic Xmas greetings program for sailors, Gruß an Bord (Greetings Aboard), on shortwave, December 24th.

Here are the frequencies from the official NDR press release [reception reports are encouraged]:

From 19.00 until 21.00 UTC (20.00 until 22.00 clock CET) on December 24, 2015:

FREQUENCY DESTINATION
6185 Atlantic – North
11650 Atlantic – South
9830 Atlantic / Indian Ocean (South Africa)
9885 Indian Ocean – West
9810 Indian Ocean – East

From 21.00 to 23.00 UTC (22.00 to 24.00 clock CET) on December 24, 2015:

FREQUENCY DESTINATION
6040 Atlantic – North
9655 Atlantic – South
9830 Atlantic / Indian Ocean (South Africa)
9515 Indian Ocean – West
9765 Indian Ocean – East

Reception reports are welcomed at [email protected].

Here are direct links just in case NRD changes a frequency:

http://www.ndr.de/info/sendungen/So-empfangen-Sie-die-Gruss-an-Bord-Sendungen,grussanbord326.html

http://www.ndr.de/info/sendungen/Gruss-an-Bord,grussanbord306.html