Here are some ways to use the word:
* "The submarine submerged beneath the waves." (completely covered in water)
* "The rising tide submerged the beach." (partially covered in water)
* "The cake was submerged in chocolate sauce." (covered in a liquid)
You can also use the word metaphorically to describe something being overwhelmed or hidden:
* "She was submerged in work and couldn't make it to the party." (overwhelmed)
* "The town was submerged in snow after the blizzard." (hidden)