Once I was been at a static competition. There was a guy who announced a 5 min static and he often had done it in the past. At this competition he got a BO in less then one minute!
So even I you feel yourself save with a 2-3 minutes breathhold, you should never do it without a partner.
I think that one of the hardest parts to learn at freediving is to follow this rule!
Concerning snorkeling and the danger of it, this could be of interest, too:
eMJA: Edmonds & Walker, Snorkelling deaths in Australia, 1987-1996