Found an interesting trivia note on Wikipedia:
"Since 1953 whenever the President is on board a military flight its call sign is the name of the armed service followed by the word "One". Thus Air Force One, Army One, Coast Guard One, Marine One, Navy One, and Space Force One. However, only the Air Force and Marine Corps actively maintain aircraft for the Commander-in-Chief, and as of January 13, 2021, the President has flown in neither a Coast Guard nor Space Force aircraft. If the President uses a civilian airplane it is designated Executive One."
Navy One referred to a Navy aircraft, and only used once (Bush). I would guess that Navy One would also apply for any other Navy transport. But....since the incoming POTUS has traditionally travelled by rail (and I assume Secret Service will no longer allow it, so this is entirely hypothetical and I'm really bored right now), what would the train be designated?
"Since 1953 whenever the President is on board a military flight its call sign is the name of the armed service followed by the word "One". Thus Air Force One, Army One, Coast Guard One, Marine One, Navy One, and Space Force One. However, only the Air Force and Marine Corps actively maintain aircraft for the Commander-in-Chief, and as of January 13, 2021, the President has flown in neither a Coast Guard nor Space Force aircraft. If the President uses a civilian airplane it is designated Executive One."
Navy One referred to a Navy aircraft, and only used once (Bush). I would guess that Navy One would also apply for any other Navy transport. But....since the incoming POTUS has traditionally travelled by rail (and I assume Secret Service will no longer allow it, so this is entirely hypothetical and I'm really bored right now), what would the train be designated?