Is it really important to wait 30 minutes after eating before swimming?
Once during our vacation last summer my daughter demanded a swim in the pool immediately after dinner. I told her to wait at least 30 minutes. Being of the age (12) that no longer accepts what I say as gospel, she insisted on an explanation. "Because my parents made me do it" was the best I could do on short notice. Was I right to insist she wait? Or was I conned by my parents?
Sorry to undermine your daughter's faith in you, pops, but you might as well get used to it. Wait till she asks you to repartition the hard drive. As you no doubt suspect, the idea that swimming right after eating means instant death is a myth.
From the 1930s through the 1950s water safety experts believed swimming after eating would lead to stomach cramps that would double you over in agony, causing you to sink like a stone. This was thought to be a leading cause of drowning. As late as 1956 the Red Cross water safety manual devoted several pages to the topic complete with staged photo of a gasping "victim."
That same year, however, University of Georgia swim coach B.W. Gabrielsen published a book called Facts on Drowning Accidents that revealed that swimming after eating was implicated in fewer than 1 percent of drownings. Thereafter the wait-an-hour hysteria began to subside. It's now thought stomach cramps are rare. It still isn't a good idea to do strenuous swimming right after eating lest you exhaust yourself. But a quick dip in the pool after dinner is harmless.
Diving in the pool, however …
There is another possible side effect to swimming after eating, which I witnessed at the impressionable age of nine. My friend Peter and our moms were visiting other friends who owned a pool. My mother refused to let me back in the water when I was done eating. Peter's mother made no such restriction and I watched with envy as he headed for the diving board. After a dramatic belly flop, Peter threw up in the pool. No more diving for anybody that day. Since then I assumed the rule was "wait an hour before you do anything violent," but that quiet paddling was OK.