I've dived to depths of one hundred feet before.
You don't have to worry because this pool is very shallow.
While diving at a depth of ten meters, I found rainbow-colored seaweed.
The water deepness is the water depth. You should check this before diving into the water so you don't hit your face.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.