The cone-shaped mountain is 4,600 metres (15,100 feet) high, 50 kilometres in diameter at its base and its summit is 1,300 metres below the surface, he said.
"Good thing a sub didn’t find it, the hard way."
According to this website, that would be almost impossible (unless we've got truly deep diving subs they're not telling us about):
"The deepest-diving large, military-style submarine was the Soviet submarine K-278 Komsomolets, with a hull made of titanium, making it very expensive, but able to withstand significantly deeper dives than the best submarines made of high-grade steel, like American nuclear submarines. The Komsomolets was a nuclear powered submarine specially designed to make trips as far down as 1300 meters (4265 feet) below sea level, definitely less than the Trieste, but very significant because the Komsomolets had to "defend" a much larger air bubble against the encroaching pressure of the surrounding ocean."Compared to the best American nuclear submarines, of the Seawolf class, Komsomolets had about 78% better diving capabilities. Seawolf submarines have an estimated crush depth of about 2400 feet (730 m). The Seawolf submarines are constructed of a high grade steel called HY-100, capable of withstanding 100 atmospheres of pressure. As a rule of thumb, the pressure increases by one atmosphere for every 10 m you descend."
1299.97 meters is equal to 0.81 miles (statute).
That doesn't sound that deep to me...
That's a lot deeper than I thought any military sub could go. But then, my expertise is from Das Boot.