Currency and shore excursions on MV Discovery

[Parapara]

We are doing a Mediterranean cruise in September on the Discovery. The brochure we have on the ship says that the currency on board is in pounds sterling, however another website says Am$. I have also heard that European cruises are in pounds and others in Am$. Can someone who has sailed on her clarify this for me please? Also on the Discovery website none of the shore excursions have prices beside them. How expensive are the shore excursions on Discovery? Are they priced in pounds or dollars? Are they good value for money? Any information would be very helpful.

Thanks!