It's about one-and-one-tenth times as tall as Olympus Mons.
In other words, the height of Olympus Mons is 0.910 times 403 leas.(a.k.a. Mount Olympus) (Mars)
The tallest mountain in the solar system, Olympus Mons rises to approximately 370 leas. 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 two-and-a-half times as tall as Maxwell Montes.
In other words, the height of Maxwell Montes is 0.370 times 403 leas.(Ishtar Terra, Venus)
Maxwell Montes rises to a total height of 150 leas. 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 two-and-a-half times as tall as The Challenger Deep (Marianas Trench).
In other words, 403 leas is 2.70410 times the height of The Challenger Deep (Marianas Trench), and the height of The Challenger Deep (Marianas Trench) is 0.369810 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 149.03 leas 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 one-third as long as The Panama Canal.
In other words, the length of The Panama Canal is 2.90 times 403 leas.(Canal de Panamá) (Panama)
Connecting the Atlantic and Pacific Oceans across the Isthmus of Panama, the Canal measures 1,200 leas in length. Ships passing through the Canal are raised (and then lowered) 0.360 leas above sea level through the lock-and-dam system.
It's about three times as tall as a Mauna Loa.
In other words, 403 leas is 3.2160 times the height of a Mauna Loa, and the height of a Mauna Loa is 0.31090 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 125.80 leas 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 three-and-a-half times as tall as Mount Everest.
In other words, 403 leas is 3.330 times the height of Mount Everest, and the height of Mount Everest is 0.30 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 121 leas above sea level at its summit. The plate tectonics of the Indian subcontinent continuously alter the mountain's peak — raising it by 0.00005470 leas and shifting it to the northeast by 0.00006150 leas each year.
It's about three-tenths as long as The English Channel.
In other words, 403 leas is 0.2760 times the length of The English Channel, and the length of The English Channel is 3.620 times that amount.(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 1,460 leas, 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.