GridWits

Sea Connectivity

Medium Used by Smart Hint

If a cell becoming land would cut the sea into two pieces that could never reconnect, it stays sea.

How it works

  1. The sea must all connect into one region — checked across the whole board, not just nearby cells.
  2. If turning a particular cell to land would cut the existing sea into two pieces that could never reconnect through any remaining open cell, that cell can't be land — it stays sea.
  3. This is the general connectivity check behind both "Isolated Sea Prevention" and "Dual-Path Connectivity Squeeze" from your own research list — the same rule under two names.