

Battleship Variations 
Besides the classic 10x10 Battleship puzzles, there are many fascinating variations. I never cease to marvel at the ingenuity of puzzle makers in creating new and challenging variations of Battleships. Here's a list of them for your enjoyment!
Description 
Comments 
Like classic
Battleships, only where the pieces are consist of five different tetrominos
(foursquared polyomino). It has a distinct feel. 

The initial puzzle board has a digit in each cell, and the board hides a classic fleet of ships. The tallies equal the sum of digits corresponding to ships. All other digits are "red herrings". I first saw this variation in the 9th World Puzzle Championship qualifying test. Here's the puzzle and Matthew Daly's analysis. Check out this complete analysis and solution of a Digital Battleships puzzle. 

The object is to place six dice in the grid such that the tallies, which are the sum of the die pips, are correct. I first saw this variation in the 9th World Puzzle Championship qualifying test. Here's the puzzle and Matthew Daly's analysis. 

Hexagonal Battleships (classic) Hexagonal Tetrominoes (from 13th World Puzzle Championship) 
Similar to classic Battleship, but the board grid consists of hexagons. The September 1999 issue of GAMES Magazine has an excellent exposition of solving Hexagonal Battleship puzzles, contributed by Gavin Stark. The May 1999 issue of World of Puzzles shows a hexagonal battleship puzzles with several tallies missing. Here is the original puzzle together with its solution. The May 2005 issue of "GAMES World of Puzzles" had Hexagonal Tetrominoes, a Hexagonal Battleship variant from the 13th World Puzzle Championship. Here is the original puzzle and its solution. Yoogi Logic Software offers Hexip, a Windows program for playing Hexagonal Battleships (see my review). 
Same as classic Battleships, but all ship segment hints are wildcards, not the actual ship segment. 

Erich Friedman's Battleship puzzles 
Erich Friedman's interesting site features many of his original puzzles, including his Battleship puzzles. There are five 3 x 1 ships hidden in a 5x5 grid, each ship with a different number from 1 to 5. The numbers at the sides of the square give the sum of the numbers on all the ships in that row or column. Each puzzle has a unique solution. Can you find it? Here's a solved example from Erich's site:
See also Erich's extremely original Battleships variants, puzzles 5  14 (many which were featured in the 9th World Puzzle Championship [October 2000]). 
Erich has added a new variation to his site: square puzzles. This puzzle type is a more generic variation of the Squared Battleships puzzle. In Squared Battleships, the types and number of ships in the fleet are known. In Square Puzzles, all that is known is that all ships are squares. 

Featured in Games Magazine's May 1999 issue (page 41). 

Featured in
GAMES September 2000 (Jane Wykes). 

Foggy Battleships  Featured on
Marcelo Inglesias's puzzle
blog site
"Acertijos y pequeños enigmas", Battleship
puzzle XIII. In this variation, there are no row or
column counts. Instead there is a plethora of ship segment
hints given. The weather is foggy, however, and it is
difficult to make out several of the hints  you know they're ship
segments but you're not sure which segments they are.

See also Marcelo Inglesias's blog site, Battleship puzzle VIII.  
Lighthouse Battleships (aka Battle Lines) 
Created by the prolific puzzle inventor Trevor Truran. See Puzzler Media web site for such a puzzle and a solver's guide (cached). 
This intriguing puzzle is, in essence, a Battleship variant. It has featured several times in GAMES Magazine, in Dave Tuller's / Michael Rios's "MENSA Math & Logic Puzzles" and "The Ultimate Clever Puzzle Book", and now on the site of the Russian puzzle club "Diogen" (see their Clouds puzzle and solution).  
Tents (in Dutch: TentjeBoompje) 
Tents
An increasingly popular puzzle, this puzzle has been printed in numerous puzzle magazines and books (e.g., Zeeslagje, Tuller and Rios's "Mensa Math & Logic Puzzles"). Here's a description of the puzzle:
Here are some links to puzzles and solutions:
Tent Pairs There is a Tents variation located on the Diogen puzzle site entitled "Tent Pairs". The description is:
Here's their original puzzle and its solution. Pentomino Camps Featuring for the first time at the 13th World Puzzle Championship (October 2004), this variation of Tents has the following description:
Click for the original puzzle and its solution. 
HouseTreeAnimal (in Dutch: HuisjeBoompjeBeestje)  A variant of
the Tents puzzle (created by Karen
de VriesGerrits?). Here's what Dave Langers writes in a newsgroup
thread:In Holland we have (or at least had) monthly editions in which I have seen such puzzles. A personal webpage in Dutch containing a similar puzzle is http://members.lycos.nl/puzzel/logica.html#Puzzel3. I suggest you mail the author of this page for more information on this type of puzzle. 
Featured in the 4th World Puzzle Championship, found in GAMES Magazine (March 1996, page 35) 

For a related variant, see SquareBox. 
From the 9th World Puzzle Championship (October 2000). Check out this complete analysis and solution of a Squared Battleships puzzle. 
Square Box  First
published in the 13th PQRST
Puzzle Championship, this is a variation of Squared
Battleships. While Squared Battleships has a known fleet to find,
Square Box does not specify the fleet to find. All you know
is that (a) all ships are squares, (b) ships cannot be adjacent, even
diagonally, and (c) The row and column tallies denote the number of
segments in each row/column.
Here is the original puzzle and its solution. 
From the 9th World Puzzle Championship (October 2000) 

From the 9th World Puzzle Championship (October 2000) 

From the 9th World Puzzle Championship (October 2000). See also Marcelo Inglesias's blog site, Battleship puzzles XI and XII. 

From the 9th World Puzzle Championship (October 2000) 

From the 9th World Puzzle Championship (October 2000) 

From the 9th World Puzzle Championship (October 2000) 

From the 9th World Puzzle Championship (October 2000). See also Marcelo Inglesias's Either/Or puzzle displayed on JuegosDeIngenio.org. 

From the 9th World Puzzle Championship (October 2000) 

From Ed
Pegg Jr.'s excellent puzzle site: 

This variation was created by Tim Peeters (first featured at the 2001 Dutch Puzzle Championship):
Be sure to check out Tim's excellent puzzle site! 

A Battleships puzzle set in three dimensions. From the 2001 MIT Mystery hunt.


MiniZeeslag ("Miniature Battleships" in Dutch) 
Miniature (6x6) Battleships board with incomplete tallies. Featured in the Dutch publication "ZeeSlagje" 
MaxiZeeslag ("Large Battleships" in Dutch) 
Very large Battleships board (larger than 10x10), usually nonrectangular in shape, with correspondingly larger ship fleets. Featured in the Dutch publication "ZeeSlagje" 
Superzwaargewichten ("Extreme Heavy Weights" in Dutch) 

Vijandelijkheden ("Armed Hostilities" in Dutch). Also known as "Black and White" Battleships. 
Very large Battleships board. The original twist is that there are two fleets (black and white) hidden on the board. There are separate tallies for the black and white fleets. No ship, even from different fleets, is adjacent to another ship. This puzzle type in 8x8 boards has appeared in GAMES Magazine (submitted by Moshe Rubin). Here's the column as published in the February 2003 World of Puzzles (it's a bit messy  the Mrs. got to it first :) ). Here's a cleaner copy as submitted to World of Puzzles. A Japanese site, belonging to Takahiko Siato, has produced 8x8 boards with a variation: ships of different fleets may be adjacent. The 16th Japanese Puzzle Championship features a 13x13 BlackandWhite puzzle. Here is the original puzzle and its solution (here are links to the full set of puzzles and solutions).

From the USA/Canada/Finland Team Qualifying Test (for the 11th World Puzzle Championship). In this variant, the puzzle is to place five Tshaped pentominoes on the board, consistent with the row and column tallies. Another example can be found in the archives of the Russian puzzle site "KIG" (December 2006, No. 52, page 9). Here is the original puzzle and the original PDF file. 

From the USA/Canada/Finland Team Qualifying Test (for the 11th World Puzzle Championship). This variant is identical to Classic (Standard) Battleships, with the additional proviso that all of the remaining cells not used by the fleet can be traversed by a single, closed loop (connecting cells horizontally or vertically). 

This Battleshiplike puzzle from the 10th World Puzzle Championship, featured in the September 2002 issue of GAMES Magazine. Although not a Battleships variant per se, it has elements of shape placement and row / column tallies. 

First published in the 3rd PQRST Puzzle Championships, this is a variation of BlackandWhite Battleships. In Level Battleships, there is one fleet (consisting of battleships, cruisers, and destroyers) above the water, and one fleet (consisting only of submarines) beneath the water. 

In this variation, the ships are replaced with thermometers. Locate the ten thermometers in the grid so they don't touch each other, not even diagonally. There are one 4unit thermometer, two 3unit thermometers, three 2unit thermometers, and four 1unit thermometers. Either a thermometer is empty or some or all of its units are filled with mercury, but always starting from its head. Numbers on the right and bottom of the grid reveal the number of cells filled with mercury. An important note: as presented in the PQRST 02 quarterly and online puzzle competition, the thermometer puzzle has multiple solutions. 

This Battleshiplike puzzle from the 11th World Puzzle Championship, featured in the April 2003 issue of GAMES World of Puzzles. A fleet is located in one grid. The ships then simultaneously move exactly 3 units forward or backwards (sideways and diagonal moves are not allowed), resulting in a second grid. Determine the initial position of the ships in the first grid and second grids. 

First appearing in the 11th PQRST Puzzle Championship, this variant is related to Moving Battleships (with tallies). As with many PQRST puzzles, Moving Battleships (without tallies) is harder to solve because of the large number of possible ship placements and the lack of tallies. Here's the authors' description:
Here is the original puzzle and its solution. 

This Battleshiplike puzzle from the 11th World Puzzle Championship, featured in the April 2003 issue of GAMES World of Puzzles. Although not a Battleships variant per se, it has elements of shape placement and row / column tallies similar to Hexagonal Battleships. 

First published in the 6th PQRST Puzzle Championship. A standard Battleships fleet is divided between two 6x6 boards. 

Cylindrical Battleships  Similar
to Wraparound Battleships, the difference being that only the columns
wrap around, not the rows.
The original puzzle was featured on Marcelo Inglesias's blog "Acertijos y pequeños enigmas" (in Spanish) as "Batalla Naval VI". 
This intriguing variation appeared in the June 2003 issue of GAMES Word of Puzzles. Created by Battleships afficionado Dave Tuller, it is Standard Battleships with a twist:
Click for the original puzzles and their solutions. Marcelo Inglesias's blog ("Acertijos y pequeños enigmas") in Spanish features a Wraparound Battleship puzzle (battleship puzzle VII). 

Takahiko Saito created this variant on his puzzle site. Following the rules of Standard Battleships, some ships can have a second floor. The segments tallies on the side and bottom include any secondfloor segments. Thanks to Otto Janko for pointing these out to me. Be sure to visit Otto's excellent Battleship site. 

First published in the 8th PQRST Puzzle Championship:


First published in the 8th PQRST Puzzle Championship:
Here is the original puzzle and its solution. Note: the original puzzle has three (3) possible solutions. 

First published in the 7th PQRST Puzzle Championship:


First published in the 7th PQRST Puzzle Championship:
Here is the original puzzle, the best solution, and a list of all solutions (both correct and incorrect) submitted. Cihan Altay, the mastermind behind the PQRST web site, is the author of the puzzle, and Scott Sheehan is to be congratulated for writing an excellent puzzle grader/solution finder. 

Created by Cihan Altay (the force behind the PQRST puzzle site) for the 2003 Google U.S. Puzzle Championship:


Submitted by Alberto Fabris for the 2004 Puzzle Design Tournament:
Here is the original puzzle and the best solution submitted. 

Created by Paul van Leeuwen for the 12th World Puzzle Championship in Arnhem, The Netherlands:
Here is the original puzzle and its solution. On 21 May 2009 Paul posted information related to this puzzle in Conceptis's puzzle forums (here's a link). Paul also provided a JPEG of the same puzzle. 

I chanced upon this interesting Battleship variant found on the site of the Russian puzzle site "Diogen". Created by Andrei Bogdanov, here is the puzzle description:


Chess Battleships (a minmax puzzle)  This
minimummaximum puzzle originated on the Diogen
puzzle web site. Here's their description:
Here is the original puzzle and its solution. 
Rhombus Battleships  Found on the
Diogen
puzzle web site, this variation requires placing nonstandard
"ships" on the board (in this case a hexagonal board).
Note that the light blue line of cells in the diagram should be ignored (it was meant as an aid for sending in the solution). Here is the original puzzle and its solution. 
Unknown Battleships 
First published in the 12th PQRST Puzzle Championship:
Here is the original puzzle and its solution. Here is a reference to this puzzle on a Japanese blog (click here for English translation). 
Russian Battleship  Featured on
the Diogen puzzle
web site,
as part of the firstround
2005 puzzle tournament. The description is as
follows:

Aiming Battleships  Another
Battleship variant featured on the Diogen puzzle web site,
as part of the secondround
2005 puzzle tournament. The description is as
follows:

TripleFleet Battleships  A Battleship
variant featured on the Diogen
puzzle web site, as part of the firstround
2004 puzzle tournament. The description is as
follows:

Battleship Observers  A Battleship
variant featured on the Diogen
puzzle web site,
as part of the secondround
2004 puzzle tournament. The description is as
follows:

Boarding Battleships  A Battleship
variant featured on the Diogen
puzzle web site, as part of the fourthround
2004 puzzle tournament. The description is as
follows:

Shuffled Battleships  Another
original
Battleship variant featured on the Diogen puzzle web site,
as part of the thirdround
2005 puzzle tournament. The description is as
follows:

Halves Battleships  A Battleship
variant featured on the Diogen
puzzle web site (called "Placing" on the site), as part of
the thirdround
2005 puzzle tournament. The description is as
follows:

Laser Battleships  A Battleship
variant featured on the Diogen
puzzle web site as part of the fourthround
2005 puzzle tournament. The description is as
follows:

PQRST Letters  First
published in the 13th PQRST
Puzzle Championship. The description is:
Here is the original puzzle and its solution. 
SingleFleet Subset Battleships  First
published on
Marcelo Inglesias's puzzle
blog site "Acertijos y pequeños enigmas"
(Battleship
puzzle XIV). This variant is a standard Battleship
puzzle with one caveat: only a subset of a standard fleet is
used. In other words, one or more ships of the standard fleet
are missing. The object, as always, is to identify the
location of the ships.
Marcelo writes that he invented this variant to prevent using the common strategy of quickly placing the battleship. 
DoubleFleet Subset Battleships  First
published on Marcelo Inglesias's puzzle
blog site
"Acertijos y pequeños enigmas" (Battleship
puzzle XV). This variant is similar to the
SingleFleet Subset variant (i.e., a standard grid contains only a
subset of a standard fleet). In this variant, however, the
fleet used is a subset of two
standard fleets.
So, for example,. the number of submarines will be 0 to 8, there may be from 0 to 2 battleships, etc. 
TwoOcean Battleships  First
published on
Marcelo Inglesias's puzzle
blog site "Acertijos y pequeños enigmas"
(Battleship
puzzle XVI). Here's a rough translation from
Marcelo's site:
Here is a copy of the original puzzle. 
Sudoku Battleship  This variant featured in the 2nd World Sudoku Championship in Prague (28 March  1 April 2007). The instruction booklet has great descriptions of a large number of Sudoku variations. 
Battleships TetraDoku (by Raymond Young)  Here's
the
description from GAMES Magazine (April 2011): "This new puzzle combines
battleships, tetraminoes, and sudoku. Place the seven ships
given below each grid into the grid such that: (1) No two ships touch,
even diagonally; (2) The total of the numbers in the squares of the
ship(s) occupying each row or column equals the number given to the
right of or above that row or column; and (3) The numbers obey sudoku
logic  that is, no digit repeats in any row, column, or 3x3 box.
After you place the ships in each grid, solve the remaining
sudoku puzzle."
Here are the original puzzles and their solutions. 