If the carrier is at port, then anything could happen. But if we are talking about attacking the carrier in battle, then the swarming tactic so often extolled by our Iranian members would not work.
For starter, there is something call the 'Douglas Sea State'...
en.wikipedia.org
We would be looking at the boats going across open water in unknown sea condition. Can the boats survive long enough to make it to the carrier and coordinate their attacks? Not likely. Anyone who has ever been 10 kts in one foot swell know what a beating the ride can be.
Next, can they escape detection? They would be detected by the two SSNs that usually accompany the fleet long before they can make it even 1/4 of the way. The subs would contact the fleet and the game would be up.
Next, can they survive the inevitable air assault?
Next, how fast are the boats? The carrier is nuclear powered and can hit 30+ kts. How long can the boats keep up assuming they somehow managed to know the carrier's position in real time? What is the boat's bingo fuel, meaning the fuel quantity that is the point of no return?