What is the main wood or steel piece that runs along the bottom of a boat or a ship?

Hint: k--l

Will give brainlest once two people answer!

The main wood or steel piece that runs along the bottom of a boat or a ship is called Keel.

Explanation:

Keel is the backbone of the ship or the boat that is used for balancing. A ship or a boat that has keel does not topple. The laying down of the keel is the first step in construction of the ship.