A royal barge is a ceremonial barge

Barge

A barge is a flat-bottomed boat, built mainly for river and canal transport of heavy goods. Some barges are not self-propelled and need to be towed by tugboats or pushed by towboats...

 that is used by a monarch

Monarch

A monarch is the person who heads a monarchy. This is a form of government in which a state or polity is ruled or controlled by an individual who typically inherits the throne by birth and occasionally rules for life or until abdication...

 for processions and transport on a body of water.

Royal barges are currently used in monarchies such as the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, Sweden

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

 and Thailand

Thailand

Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

.

Traditionally the use of royal barges was of high importance in southeast Asian monarchies such as Siam, Burma, Brunei, Riau and Cambodia.

Thailand

The Royal Barge Procession is a ceremony of both religious and royal significance which has been taking place for nearly 700 years. Some of the royal barges are kept at the National Museum of Royal Barges.

United Kingdom

The Thames was a regular thoroughfare for the Sovereign until the middle of the 19th century, on state occasions or between the Royal Palaces of Windsor, Westminster, Hampton Court, Greenwich and the Tower of London. There is currently no State Barge, but the Royal Nore, owned and maintained by the Port of London Authority, is used whenever a member of the Royal Family travels on the river Thames for an official engagement.

When the Queen is onboard the Royal Standard and Regalia are displayed and Her Majesty is always accompanied by her Bargemaster

Queen's Bargemaster

The King's/Queen's Bargemaster is a subordinate officer of the Royal Household of the Sovereign of the United Kingdom. Until the mid-19th century, the Royal family frequently used the River Thames for, but the role is now largely ceremonial...

, along with eight Royal Watermen in full ceremonial dress standing on the fore deck.