It's about twelve-and-a-half times as long as The English Channel.
In other words, the length of The English Channel is 0.0813 times 816 miles.(average width between Isle of Ushant and The Walde Lighthouse) (La Manche, Ärmelkanal, Mor Breizh, Mor Bretannek) (a.k.a. The Channel)
The English Channel measures between 66.50 miles, narrowing as it flows northeast. The world speed record for a Channel crossing by swimmer was set by Australian Trent Grimsey in 2012, with a time of 6 hours, 55 minutes.
It's about fifteen times as long as The Panama Canal.
In other words, the length of The Panama Canal is 0.067 times 816 miles.(Canal de Panamá) (Panama)
Connecting the Atlantic and Pacific Oceans across the Isthmus of Panama, the Canal measures 55 miles in length. Ships passing through the Canal are raised (and then lowered) 0.016 miles above sea level through the lock-and-dam system.
It's about 50 times as tall as Olympus Mons.
In other words, the height of Olympus Mons is 0.02 times 816 miles.(a.k.a. Mount Olympus) (Mars)
The tallest mountain in the solar system, Olympus Mons rises to approximately 17 miles. The mountain has been known to astronomers since the nineteenth century because it is tall enough to rise above Mars' frequent dust storms.
It's about 100 times as tall as Maxwell Montes.
In other words, 816 miles is 120 times the height of Maxwell Montes, and the height of Maxwell Montes is 0.0083 times that amount.(Ishtar Terra, Venus)
Maxwell Montes rises to a total height of 6.80 miles. Since Venus does not seem to have the kind of tectonic activity which gives rise to mountains on Earth, the origin of the Venusian mountain remains the subject of some dispute.
It's about 100 times as tall as The Challenger Deep (Marianas Trench).
In other words, 816 miles is 120.460 times the height of The Challenger Deep (Marianas Trench), and the height of The Challenger Deep (Marianas Trench) is 0.0083015 times that amount.(near Marianas Islands, a.k.a. Ladrones Islands, northwestern Pacific Ocean) (depth below sea level)
The Challenger Deep, at the southern end of the Marianas Trench, reaches a depth of 6.77420 miles below sea level. There has been only one manned expedition to the bottom of Challenger Deep — a 1960 voyage that took 4 hours and 48 minutes to reach the bottom.
It's about 150 times as tall as a Mauna Loa.
In other words, 816 miles is 143.20 times the height of a Mauna Loa, and the height of a Mauna Loa is 0.006983 times that amount.(Hawaii) (Hawaiian island volcano) (total height from seafloor)
Mauna Loa, one of the five volcanoes which forms the island of Hawaii and the tallest mountain in total height in the world, rises to 5.7170 miles above the seafloor. The peak of Loa is home to the approximately 6,000 sq. m (0.6 ha) Lake Waiau, one of the highest altitude lakes in the United States outside of Colorado.
It's about 150 times as tall as Mount Everest.
In other words, 816 miles is 148 times the height of Mount Everest, and the height of Mount Everest is 0.00676 times that amount.(a.k.a. Mount Chomolungma, a.k.a. सगरमाथा, a.k.a. Chajamlungma, a.k.a. ཇོ་མོ་གླང་མ, a.k.a. 珠穆朗玛峰, a.k.a. Zhūmùlǎngmǎ Fēng) (Sagarmatha Zone, Nepal and Tibet, China) (to summit, excluding snow depth)
Mount Everest is 5.50 miles above sea level at its summit. The plate tectonics of the Indian subcontinent continuously alter the mountain's peak — raising it by 0.000002490 miles and shifting it to the northeast by 0.00000280 miles each year.