Professional big wave surfers will train for this and many can hold their breath for ~4 minutes. No idea how long an average person can manage, but even 30 seco

Professional big wave surfers will train for this and many can hold their breath for ~4 minutes. No idea how long an average person can manage, but even 30 seconds under water in moderately large surf, getting tossed around and completely without any control, is a very sobering experience.