Is this static, or diving? I've done a 4:15 static, and on any given day I can do a 3:00 static after adequate preparation and a few practice holds. But my longest free dive was 1:20, and if I'd had an instructor with me I'm confident I could have made it to 1:30. But a two-minute active dive, while well within the ability of many serious freedivers, is pretty extreme and probably outside the realm of the practical for a casual recreational scuba diver.
If you are saying that all your students can hold their breath for 2 minutes while swimming, then you are teaching some pretty high-level freedivers. If you are talking static apnea, then probably anybody reading this could do it after a day learning the proper techniques. Of course, the kind of breathe-up I need to do for even a 2-minute static won't be available in a sudden OOA situation calling for a controlled free ascent. Which is why I always watch my gas carefully and stay close to my buddy.