Amidships means in the middle of a ship, halfway between the front (bow) and back (stern). When sailors talk about something being located amidships, they mean it's in that central section of the vessel.

This location matters because the middle of a ship is the most stable place to be. When waves rock a boat, the bow and stern swing up and down much more dramatically than the center does. Think of a seesaw: the ends move a lot, but right in the middle there's barely any motion. That's why ships often place heavy equipment, fuel tanks, or important machinery amidships, where the movement is minimal.

On passenger ships, cabins located amidships are popular with people prone to seasickness because they experience less rocking motion there. The term can also describe someone's position: if the captain tells a sailor to stand amidships, they're asking them to move to the middle section of the deck.