Bimaru, Yubotu, Battleship Solitaire: One Puzzle, Many Names

Bimaru, Yubotu, Battleship solitaire, Solitaire Battleships and Batalla Naval are all names for the same logic puzzle: find a hidden fleet in a grid using the number of ship squares in each row and column, with no two ships touching. It was invented in Argentina in 1982 as Batalla Naval. The other names came later, from puzzle books, magazines and publishers in other countries, and most of them simply borrow the local name of the two-player game.

This post traces the puzzle from an Argentine puzzle magazine to the world's puzzle championships, then explains the names one by one. If you want the rules first, read how to play Battleship solitaire. The history below comes mainly from the detailed account by Conceptis, a puzzle company that has supplied Battleship puzzles to publishers since 2006, which in turn draws on an email interview with the puzzle's inventor (Conceptis: Battleships history).

The names at a glance

The Battleship solitaire puzzle has collected a long list of names. Here are the main ones, with where each comes from:

Name	Language or country	Where it comes from
Batalla Naval	Spanish (Argentina)	The original name, 1982. Spanish for "naval battle", also the Spanish name of the guessing game
Battleships, Battleship	English	The usual English name, used for the Games magazine column that began in 1993
Solitaire Battleships	English (USA)	Title of the first book of the puzzles, by Peter Gordon and Mike Shenk, 1998
Battleship solitaire	English	A common descriptive name, used by many websites and apps
Zeeslagje	Dutch	A monthly Dutch magazine dedicated to the puzzle, from 1994 ("little sea battle")
Yubotu	English (USA)	Title of a 2006 Sterling puzzle book; it looks like the Japanese reading of "U-boat"
Batoru	Unclear	Listed by Conceptis among the puzzle's names; it reads like the Japanese pronunciation of "battle"
Schiffe versenken, Schiffchen versenken	German	The German names of the guessing game ("sinking ships")
Bimaru	German (Switzerland)	A trade name used by Swiss puzzle publishers, from about 2006
Ships	English	The name in Puzzle Picnic

Conceptis lists Solitaire Battleships, Yubotu, Batoru, Batalla Naval, Schiffe Versenken and Schiffchen versenken among the names the puzzle is known by today (Conceptis: Battleships history). English Wikipedia's article adds Bimaru and Battleship Solitaire (Wikipedia: Battleship (puzzle))).

Batalla Naval: Argentina, 1982

The Battleship puzzle was invented in Argentina in 1982 under the name Batalla Naval, in the puzzle magazine Humor & Juegos. Authorship is usually credited to Jaime Poniachik, who had founded the magazine as its editor in 1980. Poniachik himself described the puzzle as a team effort with three colleagues who made puzzles for the magazine with him: Eduardo Abel Gimenez, Jorge Varlotta and Daniel Samoilovich (Conceptis: Battleships history).

Poniachik was born in Montevideo, Uruguay, in 1943 and died in Argentina in 2011. He was a mathematician, editor and inventor of puzzles and games, and with Samoilovich he ran the company behind a string of puzzle magazines (Wikipedia (Spanish): Jaime Poniachik).

The very first version was not quite the puzzle we know. According to Poniachik, it appeared in issue 19 of Humor & Juegos, in February 1982, signed "J. Varli": Jorge Varlotta, a Uruguayan writer better known for the novels and stories he signed as Mario Levrero. That first puzzle, printed again in April 1982, was a variant with numbers given inside the board. Puzzles much closer to today's appeared without an author credit in issue 26, in November 1982. The only difference was the clues: a zero count was shown with a water sign, and the other counts as small black squares instead of numbers (Conceptis: Battleships history).

Whether the puzzle grew out of the paper-and-pencil guessing game, the board game, or neither is not clear. Conceptis notes that there is no clear evidence either way. The theme, though, is plainly borrowed: battleships, cruisers, destroyers and submarines hidden in a square sea. For how the two differ in play, see Battleship the game vs. Battleship the puzzle.

Five quiet years, then Enigmas Lógicos

After November 1982, Batalla Naval seems to have disappeared for five years: according to Conceptis, apparently no other Battleship puzzles were published anywhere in the world until 1987. In March 1987 the puzzle came back in Juegos Para Gente De Mente, the new name of Humor & Juegos, and this time it looked exactly like the classic puzzle of today, with plain numbers beside the rows and columns.

From June 1987, the same publisher printed Battleship puzzles in its monthly logic puzzle magazine Enigmas Lógicos, and Conceptis reports that it still does (Conceptis: Battleships history). So in its home country, the puzzle has had a regular magazine home for well over thirty years.

How Battleships reached the rest of the world

The Battleship puzzle reached an international audience at the first World Puzzle Championship, held in New York in 1992 (US Puzzle Championship: World Puzzle Championship history). Conceptis calls it an immediate success, and says Battleship puzzles have appeared in every World Puzzle Championship since.

The English name settled quickly after that:

**1993: Games magazine.** The American magazine Games introduced the classic puzzle to its readers, with Peter Gordon and Mike Shenk hosting a Battleships column. Battleship puzzles have appeared in almost every issue of Games and Games World of Puzzles since.
1993: the first variant. The second World Puzzle Championship, in 1993, introduced a version with some row and column counts missing. Dozens of variants followed, with different grid sizes, fleets and rules.
1994: Zeeslagje. In the Netherlands, Peter Ritmeester of VNU/Puzzelsport created Zeeslagje, a monthly magazine devoted to the genre. Zeeslag is the Dutch name of the guessing game (Wikipedia (Dutch): Zeeslag)), and the -je ending makes it small: roughly "little sea battle".
1998: the first book, and software. Gordon and Shenk, by then at Sterling Publishing, published Solitaire Battleships: 108 Challenging Logic Puzzles. The same year, Mountain Vista Software released Fathom It!, a shareware version for computers.
1999: Japan. Sekaibunka Publishing released the first book of Battleship puzzles in Japan.

All of these dates come from the Conceptis history (Conceptis: Battleships history). English Wikipedia gives 1997 rather than 1998 for Fathom It!, so that year is uncertain.

Dutch puzzle magazines kept printing the puzzle. When the computer scientist Merlijn Sevenster proved in 2004 that the general Battleships problem is NP-complete (hard for computers as grids grow), the example puzzle in his paper came from the July/August 2003 issue of the Dutch magazine Puzzelsport. His paper also notes that the puzzle was known as Fathom it! (Sevenster, ICGA Journal, 2004).

Yubotu: a 2006 puzzle book

Yubotu is the title of a puzzle book, Yubotu: Sink the Fleet in These Addictive Battleship Puzzles, published by Sterling in September 2006, with puzzles by Conceptis and an introduction by Peter Gordon and Mike Shenk (Open Library: Yubotu). Conceptis says it holds 180 classic Battleship puzzles in six levels of difficulty.

Retail listings for the book repeat a blurb calling Yubotu "the Japanese word for U-boat", but we could not trace that line to a source we could check. The timing fits, though: 2006 fell in the middle of the sudoku boom, when puzzle books with Japanese-sounding names were everywhere.

It is fairest to read Yubotu as a playful spelling of the Japanese pronunciation of "U-boat". Japanese writes U-boat as Uボート, read yū bōto, a loanword used for German submarines (Wikipedia (Japanese): Uボート). It is not the everyday Japanese word for a submarine. The book itself is about the classic puzzle, with the classic fleet of ten ships.

Another name on the Conceptis list, Batoru, reads like the Japanese pronunciation of the English word "battle". We could not find a primary source explaining who first used it.

Bimaru: a Swiss name modelled on sudoku

Bimaru is the name Swiss and German puzzle publishers use for the puzzle. The website bimaru.ch belongs to Küng Verlag in Zürich, which publishes Bimaru books, e-papers and an app, and lists the Rätsel Agentur among its partners (Bimaru (Küng Verlag), archived 2021). Conceptis reports that in November 2006 the Rätsel Agentur, which serves Germany, Switzerland and Austria, launched a small monthly magazine of 54 Battleship puzzles (Conceptis: Battleships history).

The story of the name itself comes from German Wikipedia, and we could not confirm it elsewhere, so treat it as the best account available rather than settled fact. It says that Bimaru first appeared in 2006 with the Taschen-Bimaru (pocket Bimaru) from the Rätsel Agentur Schweiz, that the name is a registered trademark of that agency, and that it was coined by the Zürich graphic designer Stefan Haller. The aim, it says, was a word that sounded like sudoku, with the letters "mar" to suggest the sea, without the warlike ring of Schiffe versenken ("sinking ships") (Wikipedia (German): Bimaru).

Whatever its exact origin, the name took hold in German-speaking countries, where Bimaru pocket books are sold at kiosks, and it now turns up on puzzle websites and apps in other languages too.

Why one puzzle has so many names

The Battleship puzzle probably collected its names for three plain reasons.

The theme travels with the local name of the game. The puzzle borrows its theme from the two-player guessing game, and that game already had a name in every language: batalla naval in Spanish, Schiffe versenken in German, zeeslag in Dutch, Battleships in English (Wikipedia (German): Schiffe versenken). Each country's publishers reached for the name their readers already knew.

Publishers want a name they can own. A generic name like "Battleships" is hard to trademark or tell apart on a shelf. A coined word is easier, and Bimaru, as noted above, is said to be a registered trademark. Nikoli's sudoku went the same way in reverse: the puzzle was first published in America as Number Place, and the Japanese name Nikoli gave it in 1984 is the one that went round the world (Nikoli: Sudoku). The full story is in where sudoku came from.

The sudoku boom made Japanese-sounding names fashionable. Yubotu and Bimaru both date from 2006, in the middle of that boom, and German Wikipedia says Bimaru was coined to sound like sudoku. The bridges puzzle went through the same thing, published as Hashi, Bridges, Chopsticks and Ai-Ki-Ai in different places; there is more in the story of Hashiwokakero.

Puzzle Picnic calls the puzzle Ships, which is the plainest name of all. The rules are those of the classic puzzle: a fixed fleet, row and column counts, and no two ships touching, not even at a corner.

Frequently asked questions

Is Bimaru the same as Battleship solitaire?

Yes. Bimaru is the name Swiss and German publishers use for the Battleship puzzle: a hidden fleet, numbers beside every row and column, and ships that never touch, not even diagonally. The rules are the same, though grid sizes and fleets vary from publisher to publisher.

Who invented the Battleship puzzle?

It was invented in Argentina in 1982 at the puzzle magazine Humor & Juegos. Authorship is usually credited to the magazine's founder, Jaime Poniachik, who described it as a team effort with Eduardo Abel Gimenez, Jorge Varlotta and Daniel Samoilovich.

What does Yubotu mean?

Yubotu is the title of a 2006 American book of Battleship puzzles. It is usually explained as Japanese for "U-boat", and it is best read as a spelling of the Japanese pronunciation of "U-boat", yū bōto, rather than an everyday Japanese word for submarine.

Is Bimaru a Japanese puzzle?

No, although the name sounds Japanese on purpose. The puzzle comes from Argentina, and according to German Wikipedia the name Bimaru was coined in Switzerland in 2006 to sound like sudoku.

Is the Battleship puzzle the same as the board game Battleship?

No. They share a theme, but the board game is a two-player guessing game and the puzzle is a one-player logic puzzle with a single solution. Battleship the game vs. Battleship the puzzle compares them side by side.

Where to go next

Whatever you call it, the puzzle is the same, and the techniques carry over between every book, magazine and app. To learn to solve it, start with how to play Battleship solitaire, then move on to the Battleship solitaire strategy guide, which solves a full 8x8 grid step by step. Everything about the puzzle is collected on the Ships topic page.

You can play it as Ships on Puzzle Picnic, in the browser or in the app, at four levels from a 6x6 Easy grid to the classic 10x10 fleet.