The deepest part of the ocean is the Challenger Deep, located in the Mariana Trench, with a depth of about 10,900 meters (roughly 35,800 feet) below sea level. Context and quick facts:

• The Mariana Trench sits in the western Pacific Ocean, east of the Mariana Islands. The trench is the longest and deepest oceanic trench on Earth [web results indicate Challenger Deep as the deepest point within the trench].

• Depth measurements have varied slightly over time due to measurement methods, but a commonly cited value is approximately 10,984 meters (around 36,037 feet) for the deepest point, Challenger Deep, within the Mariana Trench.

• The name "Challenger Deep" honors the HMS Challenger expedition, which first mapped the trench in the 1870s, establishing it as the deepest known point in the oceans.

If you’d like, I can provide sources or a concise summary for teaching slides, or compare Challenger Deep depths from different measurement campaigns.