Location: Graveyard

Depth: 307

Depth: 307

These are ordinary battleships puzzles (Bimaru), with the addition of a 3-unit submarine.

Due to being underwater, the submarine is not constrained by the location of normal ships or given water squares.

In the solutions below, the submarine is shown as the highlighted blue squares.

**Puzzle 1:**

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3 | 1 | 1 | 0 | 11 | 0 | 1 | 3 | 1 | 2 |

**Puzzle 2:**

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6 | 0 | 2 | 3 | 2 | 2 | 0 | 4 | 1 | 3 |

**Puzzle 3:**

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1 | 3 | 1 | 0 | 9 | 0 | 2 | 3 | 3 | 1 |

**Solution to Puzzle 4:**

Notation: Label the rows and columns 1 to 10. R1 is the topmost row, C1 is the leftmost column, and R1/C2 is the second square in the top row.

There are two possible locations for the battleship: one in C8 and one in R10.

If the battleship is in C8:

- The possible cruiser locations are in R3, R10, and C1.

- However, C1 can be ruled out because it leaves no location for the sub.

- Meanwhile, if the cruisers are in R3 and R10, then the sub now must intersect C7, but it cannot.

So the battleship is in R10. Notice that the sub must intersect R9.

If the sub is vertical:

- The sub cannot be in C1, since R9/C1 must be occupied by a normal ship. The sub has to be in R7-9/C8.

- Then there are two possible cruiser locations, in R3 and R6, but they cannot co-exist.

So the sub is horizontal in R9. Notice that the sub must intersect R9/C3.

Since C3 is full, the unblocked cruiser locations are in R3, C1, and C8.

If a cruiser is in R3, then the sub extends left and the other cruiser is in C8. But now we can no longer fill C7.

Therefore place the cruisers in C1 (intersecting R7/C1), and at the top of C8.

The cruiser in C1 implies the sub extends to the right, and since R5/C2 is blank it also extends to the left.

A little trial and error will finish the puzzle (there are too many frigates if the R1 cruiser extends up to R5).

**Puzzle 4:**

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3 | 2 | 3 | 1 | 2 | 1 | 2 | 6 | 1 | 2 |

**Solution to Puzzle 5:**

Condition on the ship that uses the black square in the middle.

If it is horizontal, then it must be a cruiser. And the battleship is in R9/C1-4.

- A frigate is in R4/C10. The sub must be in R6-8/C6 or R6-8/C7. The other cruiser must be in C2.

- If sub in C6, then a destroyer is in R9, leaving R10 unfillable. If C7, then there's not locations for destroyers.

So the center ship is vertical. We can now safely fill in C5.

The sub must intersect C7. (Else we fill in C7, then can't fill C8.)

If the sub is horizontal it intersects C6, so C6 contains a cruiser.

- Then R9 must contain the battleship and a destroyer, which leaves both R8 and R10 unfillable.

So the sub is vertical in C7. Notice it must include R8-9/C7.

C6 contains the battleship, or there's too many frigates with R3 and R7.

A cruiser can be in R1 or R9, but not both, so one cruiser is in C2.

There are too many frigates between R3 and R7 unless the sub extends up (into R7).

Similarly the section R9 to the right of C6 is a destroyer. A little trial and error will complete the puzzle.

**Puzzle 5:**

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2 | 4 | 1 | 3 | 1 | 4 | 4 | 2 | 0 | 2 |

To extract, read the letters from the grid corresponding to the locations of the subs, in puzzle order. This gives READ ODD FRIGATES.

Finally, take every other frigate in puzzle order, reading left to right and top to down. This gives the answer, SMS POMMERN.

S_{1} | H | O | N | C | M_{7} | I | A | O | Q | |

U | N | I | A | S | O | O_{5} | C | U | R_{9} | |

L | C | D | O | D | R | N | O | S | E | |

O | N | I | E | F | C | N | M | T | L | |

A | S | I | W | R | I | O | E | T | N_{10} | |

D | O | G | S_{3} | N | T | E | E_{8} | L | E | |

L | M_{6} | A | C | R | S | T | X | J | B | |

T | V | E | I | E | A | E | M | G | T | |

E | I | G | A | A | N | S | I | K | Y | |

M_{2} | K | Q | I | U | P_{4} | M | Z | A | D |