[This is a repost from our archives with new notes at the top (original post here): My very first book from Sterling Publishing (their name at the time) was Battleship Sudoku, taking one of my livejournal puzzle ideas and turning it into a full-sized book. While the combination is simple in its rules as other Sudoku variations more commonly featured here, I found I could write a lot of interesting puzzles by slowly placing sets of numbers into the grid via the outside clues. The future “Shape Sudoku” style would be motivated by seeing how placing groups of numbers all at once (maybe with rotations) from the fleets worked very well to hide different sudoku deductions.]

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between number placement, ship placement, and shading modes. The shading mode in gray, which numbers can be written on top of, may work better than default ship placement.)

Theme: Even Steven; the fleet has only certain kinds of numbers.

Rules: Standard Battleship Sudoku rules.

Estimated Difficulty*: 2 stars

Time Standards (highlight to view): Grandmaster = 1:30, Master = 2:15, Expert = 4:30

Solution: PDF