Can you get married by an airline pilot over international waters?

Flights seldom take more than 12 hours so there is no need for airline staff to conduct weddings.

Code of Federal Regulations, Title 32, Subtitle A, Chapter VI, Subchapter A, Part 700, Subpart G, Rule 716, also known as 32 CFR 700.716):

"The commanding officer shall not perform a marriage ceremony on board his ship or aircraft. He shall not permit a marriage ceremony to be performed on board when the ship or aircraft is outside the territory of the United States, except: (a) In accordance with local laws … and (b) In the presence of a diplomatic or consular official of the United States."