Why are all the DS9 runabouts named after Earth rivers?

Question

It seems whenever we hear mention of a runabout assigned to DS9 it's named after a river on Earth—the Rio Grande, the Ganges, the Yangtzee Kiang—is there a particular reason for this naming convention?

Answer 1

It is common in the US navy to name all the sister ships of the same construction class, or even all the ships with similar functions -battlesips, cruisers, aircraft carriers, oilers, torpedo boats, with theme names.

United States ship naming conventions for the U.S. Navy were established by congressional action at least as early as 1862. Title 13, section 1531, of the U.S. Code, enacted in that year, reads, in part,

The vessels of the Navy shall be named by the Secretary of the Navy under direction of the President according to the following rule: Sailing-vessels of the first class shall be named after the States of the Union, those of the second class after the rivers, those of the third class after the principal cities and towns and those of the fourth class as the President may direct.

https://en.wikipedia.org/wiki/United_States_ship_naming_conventions#:~:text=The%20vessels%20of%20the%20Navy,the%20principal%20cities%20and%20towns

And some of those rules may have been followed earlier. The last class of ships of the line of the US navy, the seven Delaware class ships started in 1820, were all named after states of the Union.

https://en.wikipedia.org/wiki/List_of_ships_of_the_line_of_the_United_States_Navy

USS Merrimack, also improperly Merrimac, was a steam frigate, best known as the hull upon which the ironclad warship CSS Virginia was constructed during the American Civil War. The CSS Virginia then took part in the Battle of Hampton Roads (also known as "the Battle of the Monitor and the Merrimack") in the first engagement between ironclad warships.

Merrimack was the first of six screw frigates (steam frigates powered by screw propellers) begun in 1854. Like others of her class (Wabash, Roanoke, Niagara, Minnesota and Colorado), she was named after a river. The Merrimack originates in New Hampshire and flows through the town of Merrimac, Massachusetts, often considered an older spelling which has sometimes caused confusion of the name.1

https://en.wikipedia.org/wiki/USS_Merrimack_(1855)

So that is a precedent for a class of ships named after rivers.

Battleships (hull code BB), by law, were named for states, except for USS Kearsarge (BB-5), which was named after a mountain in Merrimack County and an American Civil War sloop-of-war.

Cruisers, both light and heavy (CL and CA), were named for cities in the United States and its territories, with the exception of USS Canberra (CA-70), which is named after HMAS Canberra (D33) and Canberra, the capital of Australia, making USS Canberra the only U.S. warship named for a foreign warship and foreign capital city.

Aircraft carriers, both with conventional and nuclear propulsion, (CV and CVN), have a history of various legacy names, mostly battles, until 1968, with the commissioning of USS John F. Kennedy (CV-67). Since then, carriers have been named for U.S. presidents, with the exception of;

ships named Enterprise; there is a continuing exception for this name, first used in 1775, eight ships have carried the name, three of them aircraft carriers (CV-6, CVN-65 and CVN-80).

USS Nimitz (CVN-68), lead ship of her class, named for Fleet Admiral Chester W. Nimitz, commander of all U.S. and Allied naval forces in the Pacific theatre during World War II,

USS Carl Vinson (CVN-70), named for a former Congressman, Chairman of the Naval Affairs Committee, Chairman of the successor United States House Committee on Armed Services, a strong supporter of the Navy through the Naval Act of 1938 (also called the "Vinson Acts") who became known as "The Father of the Two-Ocean Navy",

https://en.wikipedia.org/wiki/United_States_ship_naming_conventions#:~:text=The%20vessels%20of%20the%20Navy,the%20principal%20cities%20and%20towns

And every type of ship or construction class within a type seems to have a naming convention.

USS John C. Stennis (CVN-74), named for a former United States Senator, President pro tempore of the Senate, Chairman of the United States Senate Committee on Armed Services, and a strong supporter of the navy, who became known as "Father of America's modern navy".

Answer 2

Star Trek appears to use current and historic naval traditions of theming a class of ships

The NX-Class ships were all named after space shuttles.

Since the USS John F Kennedy, US aircraft carriers have been named for people - presidents or admirals/generals. Before that, there have also been themes of naming them for battles but that was not consistent. Battleships and cruisers were named for US states and cities respectively.

From the 20th century, the Royal Navy named capital ships after famous ships of the past, which, to be fair, they’ve had a lot of. Other classes were named alliteratively: Basilisk, Beagle, Blanche, Boadicea, Brazen, Bulldog; Danae, Dauntless, Dragon, Durban, Diomede etc,

The Royal Australian Navy has a tradition of naming (and renaming) ships for towns and cities: there have been 4 Sydneys, 3 Melbournes, 3 Perths, and 4 Parramattas. The RAN has also reused names of merchant vessels that were pressed into service such as HMAS Kanimbla named for the merchant ship commandeered in WWII.

So, the tradition among anglophone navies at least is to a) recycle names and b) come up with a theme (however lame) and stick to it, and c) throw all that out the window and do what you want.