Not only that, but also with a buddy you better avoid doing statics at the pool bottom. Even if the buddy is watching you, he may not react quick enough, and before he rescues you in case of troubles, you may already inhale water and finish then in hospital. And that's the better case. There unfortunately far too many people dying in this way in pools each year.
Do static apnea on the surface in a shalow pool, having you buddy standing at you, regularly checking with you if you answer agreed signals (tapping on the shoulder, or clicking the hand), and pulling you out immediately when you fail to answer a repeated signal. You can black out or lose motor control easier than you think, and often with no warning signs (especially if you hyperventilate).
We often reffer to the following thread, at fool newbies practicing breath-holding in unsafe way:
http://forums.deeperblue.com/safety/68814-bad-news-sweden.html Unfortunately in the mean time there were other accidents anyway too.