By pumping water or air into the ballast tanks.
ascend and descend
Fall-Rise Descend- Ascend
Descend.
Width
Width
The antonym of "descend" is "ascend." While "descend" refers to moving downward, "ascend" means to move upward. Both terms are commonly used in various contexts, such as climbing, altitude changes, or figurative situations like progress or status.
Depth
Width
Depth. To ascend is to go up, and to descend is go down. We measure the height of things above the ground and the depth of things below the ground.
The opposite is descend (go down the stairs).
lift.... Gravity
The antonyms for deduct is to add, to increase, to raise.