Britain's newest aircraft carrier, HMS Prince of Wales, has sailed into Liverpool for a week-long visit.
The ship is one of two giant new carriers, partly built at the Cammell Laird yard in Birkenhead.
More than 13,000 people are due to go to onboard the 65,000 tonne vessel during her stay, after tickets were given away free online.
Officers say they want everyone to have a "safe and enjoyable time." They add the presence of armed officers and police dogs is not a response to a "direct threat," but simply a way to keep the public safe at busy events.