Cruise ships have named celebrity 'godmothers' including Oprah Winfrey, Queen Elizabeth, and Nicole Scherzinger. Here's what the role involves.

• Nicole Scherzinger has been named the "godmother" of P&O Cruises' newest ship.
• The Pussycat Doll is the latest in a long line of celebrity godmothers.

Nicole Scherzinger has been named the godmother of P&O Cruises' newest ship, Arvia.

The singer, best known for fronting the Pussycat Dolls, is the latest in a long line of celebrity godmothers. Some of the most famous figures to take the role include Oprah Winfrey, Queen Elizabeth, and Katy Perry.

Scherzinger will attend the ship's naming ceremony in the Caribbean on March 16 and perform at the event.

P&O Cruises also said the singer was joining them as "part of a special partnership" to help create the music and dance entertainment performed on board its ships.

The pop star and "The X Factor" judge said in a statement reported by several outlets: "I have always felt as though I am honorary Brit and to be asked to name Arvia in Barbados really is the icing on the cake and I cannot wait to perform my godmother duties in the most beautiful of Caribbean locations."

Here's where a cruise ship's godmother is and what the role includes.

What is a ship godmother?

A cruise ship godmother is a long-standing tradition. A largely honorific title, the godmother is supposed to bring a vessel good luck and protection.

In naval tradition, the role is taken by a civilian woman but now celebrities or royal family members are the most common kind of godmother. Some of the more famous godmothers or fathers include Jennifer Lopez, Mariah Carey, and Pitbull, according to The Mirror.

Several cruise companies, including Norwegian, have a mixture of ship godmothers and godfathers.

Naming a cruise ship godmother is also a marketing initiative, celebrities sponsoring ships brings more publicity and build excitement for the launch of a new ship.

What does the role involve?

The role is mainly centered around a ship's naming ceremony. Godmothers must attend the event and officially bless and name the vessel.

Traditionally the godmothers would also crack a bottle of champagne against the ship's bow to bring it luck.

As ships got bigger, this tradition was tweaked slightly. These days the job involves pressing a button to trigger a bottle to swing down and smash on the ship.