Castles · 舟囲い
Boat.
The quickest castle on the left: the king aboard on 7h with the bishop as the hull. Seven moves, three of them pawns.
How it goes together
Japanese sources name this castle as a whole shape rather than as generals alone: bishop 8h, king 7h, silver 7i, gold 6i, gold 5h, silver 4h. Read it as a hull with the king riding in it and the name explains itself. Three of those pieces never move at all, which is where the speed comes from: the king steps to 6h and 7h, the right silver comes up to 4h, the right gold to 5h, and the castle is finished.
Move by move
Black only, from the start position. The 7f pawn, the right silver to 4h, the 5f pawn, the king to 7h, the right gold to 5h, and the edge pawn last.
Step through the moves, or press play.
Tap a move to jump to it. Arrow keys work once the board has focus.
Seven moves and the king is out of the middle. Compare the Anaguma’s eleven: this is the trade the boat castle is offering.
What it is good against
Speed, and not much else. It is finished before a ranging rook has finished a Mino, so the moves it saves go into an attack: a Climbing Silver or a Right Fourth File Rook is built on top of this castle. It is also the sensible first castle for a beginner facing a ranging rook, because it is short and hard to get wrong.
Where it breaks
It is thin, and everybody knows it. There is one general in front of the king and no second layer behind that, so a ranging rook attack that gets going tends to reach the king quickly. The bishop is part of the wall: trade it off and 7g, the square directly above the king, loses a defender. This is the castle you upgrade, into a Left Mino or an Anaguma, if the game gives you the moves.
When to build it
Facing a ranging rook when you mean to attack first, or as the first thing you build while you wait to see which of the bigger castles the position wants.
Build it at the board.
The app’s lesson walks the king into a Mino one step at a time, and its review names the castle you were building when a game turned.