How deep is the deep end of the ocean? The answer turns on an array of factors nearly as wide as the sea itself: the barometric pressure over the site in question, the seawater’s density and temperature, the vagaries of measurement and, perhaps, on whether a world record is at stake.

The whereabouts of the planet’s deepest spot is widely agreed upon: the Challenger Deep, a muddy depression nearly seven miles down in a long fissure of the western Pacific, 200 miles southwest of Guam. The depression is estimated to be roughly a mile wide and seven miles long .

In April, Victor L. Vescovo, a rich investor who has skied the North Pole and climbed Mount Everest, piloted a submersible — part of a $48 million operation — into the Challenger Deep and declared his dive the deepest ever by a human. Global headlines followed. The record depth was given as 35,853 feet — a first by 52 feet, according to the team’s official statement.

Last month, Mr. Vescovo raised his profile further by making the final dive of what his team called “the world’s first manned expedition to the deepest point in each of the five oceans,” a list that includes the Challenger Deep. The Discovery Channel will feature the dives in a five-episode series.