Thanks to the Watchmaster Site I have had a look around and found that Muriel wears a G-shock in 'Einsatz Hamburg Süd'
You can see it clearly in this clip from 19:45 onwards:
http://serialsonline.net/clip/105338.html
She wears a different watch in the second series. Her co-star also wears a cool watch in this clip from about 3:20:
http://serialsonline.net/clip/105334.html