I've done a search for recent videos of college swimming and it looks like speedos are the preferred suit.
I tried to count the number of swimmers wearing speedos VS jammers and it looks like at least 90% of them are wearing speedos:
https://www.youtube.com/watch?v=M7ofp2Uz14I
https://www.youtube.com/watch?v=yXEn9ucw1dg
https://www.youtube.com/watch?v=TvZ9G8xqL7k
https://www.youtube.com/watch?v=QpWD3Eazlcc