Solver Rule: End Segment has an Adjacent Segment Wildcard

By definition, all end ship segments (i.e. top, right, bottom and left) have another ship segment connected to them.



In the example above, the left ship segment at (H,2) must have a neighboring ship segment at (H,3).

Even if you don't know the exact type of ship segment (in the example above, (H,3) might be a right or middle ship segment), you can finalize the square as a segment wildcard (a diamond-shaped segment).