Thousands gathered in London to urge Scottish voters to reject independence and stay in the United Kingdom in a landmark referendum in three days' time.
The yen fell again against the dollar and euro while the pound edged higher amid polls in Scotland showing a small majority against breaking from the UK.
Scotland's pro-independence leade said the "eyes of the world" were on a referendum next week as officials reported record numbers registering to vote.
Support for Scottish independence is increasing ahead of a referendum, amid attempts by David Cameron to make the business case for retaining the union.
Queen Elizabeth II smashed a bottle of whisky against Britain's biggest warship as she gave her name to the new aircraft carrier at a ceremony in Scotland.