What currency to tip with?

[RubyGold]

We'll be on the Explorer out of Southampton (port that uses pounds sterling ) going to Paris and Bruges (use euro) but the line its self uses dollars as currency.

 

If tipping drinks or room service or the like, what should I use?

[BekkaW]

We always take some $US with us, but the staff will be happy to accept any currency

[uksimonusa]

The staff can spend dollars onboard, pounds in the UK, and Euros in Europe, so anything is good for them.