What does "topside" refer to on a ship?

Topside refers to the upper parts of the vessel that are situated above the main deck. This includes areas such as the bridge, forecastle, and any upper working spaces or decks that are not covered by the main deck. Understanding this term is crucial for effective communication onboard a ship, as it helps identify locations for various operations and safety measures. The topside areas are typically where much of the ship's navigation and external activities occur, so knowledge of these regions is important for all crew members.