let me entertain you gentlemen and ladies for a few moments:
the uss george h w bush is the newest, largest ship in our navy. it has a beam length of 1092ft, and a flight deck area of 4.5acre (196018ft2). now, assuming the deck to be a square (a stretch but let me explain), that leaves us with 179ft width.
so our constraints are a rectangle with 179ft width and >1000ft length.
a 200m indoor track is typically 23.9m (78ft) radius. this gives us the inside of lane 1 occupying 156ft.
so now we have the inside oval painted on the carrier, and we have 11.5 ft to spare on either side. make 4 lanes, each one 2.5 feet, and we have a 4 lane track on an aircraft carrier.
despite the assumption that the carrier was square, we can manipulate the shape of the track a little bit (not parallel straights) to suit the real estate were working with. its been done before.
someone said that waves would make it like running in an earthquake: tell me that anything other than the perfect storm would be able to rock a 103000ton ship. and wind can be negated by moving the ship with the wind.
as for viewership, im sure people watched the millrose games, and those were on a much smaller track, in a way less unique setting. if you build it, they will come.
now we just need to figure our how to borrow a $6.2B defense asset...