I've tried (several times) and failed to find a way to get the two of them talking either before, during or after one of the swimming sessions.

That's because men don't talk. (This is coming from my husband, btw.) Especially in locker rooms. Particularly when wearing Speedos. Such a thing could be construed as *gasp* GAY. (Not that there's anything wrong with that.)

Can you have them meet somewhere other than the pool? Like in the cafeteria, or at a bar, or during class? It might be easier to get them talking about something if they're away from the pool, and recognize each other from all those attempted conversations.