

Battleship Omnibus 
On this page you'll find a comprehensive collection of everything related to the Fathom It! / Battleships concept, including board analyses and links to related sites.

Battleship Variations (VERY interesting!) 
Lots of mindexpanding variations on the classic Battleships. 
Here you'll find indepth analyses of boards found in Fathom It!'s board database. 

Puzzles #17 and #18 are 9x9 Battleship puzzles. The solutions are also provided. As a bonus, Matthew Daly provides his analyses of the two puzzles. The puzzle and solutions for each can be found at: 

The 1999 World Puzzle Championship Test 
Includes classic battleship puzzles and 4 variations (e.g., combination of the Battleships and the Minesweeper puzzles). View the Battleship puzzles here. 
To see the test, download the Adobe PDF version. Puzzle #6 is a 10x10
Battleships puzzle. The puzzle and solutions
for each can be found at: 

To see the test, download the Adobe PDF version. Puzzle #8 is a Classic
10x10 Battleships puzzle (Moshe Rubin). 

Here's
the Adobe PDF version. The password to open the document is
"wbloF7eldw". It contains three Battleshiptype puzzles: a classic
(standard) one, a " 

Analyses of past Battleships columns in "GAMES Magazine" and "World of Puzzles" 
For those of you with back issues of GAMES or World of Puzzles, you'll find analyses of previous columns. So pull out those old issues and try your Battleships skills. 
WeiHwa's Solitaire Battleships Times, and some Battleships Strategies 
WeiHwa Huang, fourtime winner of the World Puzzle Championships, timed himself while solving all 108 Battleships problems in Peter Gordon and Mike Shenks book, "Solitaire Battleships: 108 Challenging Logic Puzzles". His summary makes fascinating reading. 
An attempt to analyze a class of puzzles (including Fathom It!like Battleship puzzles). Here's a quote from the monograph:
"I would then like to consider the new puzzle of whether we can know which of the puzzles are uniquely solvable. If we can answer this question, then theoretically, we could crank out hundreds of puzzles." 

A monograph entitled "Minesweeper and the "P=NP?" question: a short FAQ" 
Within the article, discusses Battleships:

Minesweeper and the P=NP question

An interesting site, even if not directly connected to Fathom It! puzzles. Here's a quote from the :

Article entitled "Battleships as Decision Problem" (published in ICGA Journal, September 2004)  This article,
authored by Merlijn Sevenster and published in the September 2004 issue
of ICGA (International Computer Games Association) Journal, is a
commendable attempt to show that solving Battleship puzzles is
NPhard. Here's the abstract:
Cached files: 1 
Article: "Explain P = NP problem to 10 year old"  Excellent set of slides by Geoffrey De Smet explaining why the bin packing problem is so difficult to solve. 
Bob Abrahamian's final project for CS 205 (Department of Computer Science, University of Chicago) entitled "Playing Battleship Puzzles" (Link is currently BROKEN, awaiting response from University of Chicago) 
Quote from the paper:

Paper (in PDF format) entitled "Satisfiability Encodings (04)", There is also an HTML online version of the paper. 
From Michael L. Littman's course in Numeric Artificial Intelligence at Duke University. Discusses solving Battleship puzzles using satisfiability (SAT) methods. 
A description of the Battleships puzzle genre on the Everything2.net website. 
The Everything2.net website is a very complex online community with a focus to write, publish and edit a quality database of information, art and humor. 
Other Internet sites related to Battleships logical puzzles

You can translate the foreign language pages using Google Translate or any other service. (Years ago I recommended AltaVista's BabelFish online translation service which is now defunct. Read Brenda Barron's fascinating history of the BabelFish service.) 
Marcelo
Inglesias's puzzle blog "Acertijos
y pequeños enigmas" carries many
delightful Battleship puzzles, both classic and variants
(Marcelo admits that Battleship puzzles are his favorites).
To date he has presented the following Battleship variants:
The JuegosDeIngenio.org site carries a guest article of Marcelo's together with an Either/Or Battleships puzzle of his creation. 
Here's a
picture of Marcelo
Inglesias (taken from JuegosDeIngenio.org):
To translate the pages I recommened using Google Translate. Just paste the URL into the left window in "text" mode, setting the right window to your preferred language. Google will give you a link to the translated page and you're good to go! 
Yoogi Logic Software offers "Hexip", a Windows adaptation of Hexagonal Battleships. 
I flatter myself that Hexip was inspired, and takes most of its interface and features, from Fathom It!. By all means, download a copy and play it. The author did a nice job implementing the features. In my opinion, however, the Hexip solver does not relate to the fascinating techniques for solving Hexagonal Battleship puzzles as expounded in Gavin Stark's monumental analysis in September 1999 issue of GAMES Magazine. Nonetheless, if you enjoy Fathom It!'s Standard Battleship puzzles, you'll enjoy Hexip. 
Takahiko Saito's interactive "BtlSez32" Windows program.  Takahiko
Saito offers his "BtlSez32"
Windows program for setting up custom Battleship puzzles and solving
them interactively.
Here's a partial list of BtlSez32 features:
Summary: This is obviously a work of love and a positive step in helping puzzlers enjoy Battleship puzzles. 
Dark Chrome Software offers "Battleship Sudoku", a Windows adaptation of Solitaire Battleships.  A recent entry into the Solitaire Battleships market, this program has nothing to do with Sudoku but everything to do with Solitaire Battleships. 
Constraint
Programming and Battleship puzzles

Constraint programming is a programming paradigm in which a set of constraints that a solution must meet are specified rather than set of steps to obtain such a solution. It can be used for solving Battleship puzzles. 
LEGUP:
Logic Engine for GridUsing Puzzles
LEGUP (Logic Engine for GridUsing Puzzles) is an Undergraduate Research Project under Dr. Bram van Heuveln in the department of Cognitive Science. It is under the greater classification of "Visual Logic", as it is a system of logic that is based purely on applying rules to objects visual in nature. 
From the
LEGUP web site:
As I understand it, the project hopes to create a logical solver for a host of puzzles including Battleships. Check out the Battleship PowerPoint file listing numerous rules for solving Battleship puzzles. To date, all the rules found there are taken from the Fathom It! documentation and solver. It will be interesting to see if they discover new solving rules. 
"Problem solving in
IDlogic with aggregates: some experiments" (Authors: Van
Nuffelen, Bert; Denecker, Marc)
In this paper the authors attempt to design an expressive logic, suitable for declarative knowledge representation. One of the experimental problems they use in testing their work is Solitaire Battleships. The authors define the problem in declarative terms. 
Quoting the
abstract from the paper:

Constraint Programming Models for
Solitaire Battleships Barbara M. Smith Cork Constraint Computation Centre, University College Cork, Ireland 
Quoting the
abstract from the
paper:

PuzzleSolving
the Battleship Puzzle as an Integer Programming Problem W. J. M. Meuffels Tilburg University, 5000 LE Tilburg, The Netherlands, and ORTEC, 2800 AL Gouda, The Netherlands, ineke.meuffels@ortec.com D. den Hertog Tilburg University, 5000 LE Tilburg, The Netherlands, d.denHertog@uvt.nl 
Quoting
the
paper's abstract: One’s
aim in solving logical puzzles is to find the solution by making use of
several clues and restrictions. In this paper, we solve a logical
puzzle, the Battleship puzzle, by integer programming. Moreover, two
integer programming models (i.e., a cellbased model and a shipbased
model) for the Battleship puzzle are compared based on their complexity
and solution times. The shipbased model requires more preprocessing
work before running the integer program than the cellbased model, but
strongly outperforms the latter one. Finally, the models are used to
check if a puzzle contains redundant information and to create a puzzle
with a unique solution.
The paper can be access here, and sample code (written in the AIMMS programming language) can be downloaded from here (material is cached here) 
Discussion about "false" NxN Battleship puzzles (from the now defunct bbcmindgames.com puzzle forums)  A question
I've considered over
the years is"
are "false" 10x10 Battleship puzzles considered 10x10
puzzles? A "false 10x10" puzzle is a Battleship puzzle that
has 10 rows and 10 columns, but where one or more rows/columns could be
removed without changing the puzzle.
Here's an example: Notice the two rows and one column with zero counts on the extremities of the board. This puzzle has 10 rows and columns but is really an 8x9 puzzle: The thread contains the question and several replies. 
Niels Roest (member of the Dutch team at the World Puzzle Championship) wearing a Battleship Tshirt.  I came across this photo while perusing a page on the Japanese Puzzle Championship site. The page highlighted the backs of several contestants' Tshirts, including Niels Roest's Battleshipthemed Tshirt sponsored by Puzzlesport worn at the 15th WPC in Borovets, Bulgaria. 
The CYBIRD Group (Japan) advertised playing Battleship puzzles on cellphones back in 2001.  The Japanese
mobilephone company CYBIRD advertised a service for solving Battleship
puzzles on mobile phones back in 2001. Here's the page
in Japanese and the same page translated
into English.
Note that the puzzle above is identical to the puzzle on the front cover of Sekaibunka's "Battleships #1" puzzle book: 
How to handcraft your own Battleship puzzles (Mike Selinker's and Thomas Snyder's "PuzzleCraft #48: Battleships" column in GAMES Magazine, February 2009).  Tom
Selinker has a wonderful ongoing series of articles in GAMES Magazine
entitled "PuzzleCraft", describing how to create your own homespun
versions of popular puzzles including crosswords (#5  #7), quote boxes
(#9), logic puzzles (#10  #11), diagramless crosswords (#14), Sudoku
(#18), Kakuro (#27), Solitaire Hangman (#31), and many more.
In
the February 2009 issue he tackles the task of creating Battleship
puzzles by hand. Here is a set of four handcrafted Battleship puzzles, and here is a detailed explanation of how to create Battleship puzzles. 
The German website www.sachsentext.de, dedicated to puzzles in general, has several pages of Battleship variants in English.  The battleship
variants include: "T it up" Battleship
Sudoku
"T it up"Battleships At the right place Battleship Sudoku Confused Battleships Crowded Battleships Diagonal Battleships Double Fleet Subset Battleships Even Battleships Sudoku Lighthouse Battleships Minesweeper Battleships Mini Fleet Sudoku Odd Battleship Killer Single Fleet Subset Battleships Squared Battleships Submarines Tank Search Tetris Battleships Wildcard Battleships 