Great discussion. Now, moralizing aside, let me contribute as a former prosecutor, now defense attorney who's work includes alcohol related driving and criminal offenses, and who has published in that filed years ago. First, everyone metabolizes alcohol at different rates, but there are some norms that create useful guidelines. Second, it does not matter if you eat while consuming alcohol or not: the critical factor for alcohol impairment is how much alcohol you have consumed and when. Third, 12 ounces of beer, or 4 ounces of wine, or one ounce of liquor each contain approximately the same amount of alcohol. Fourth, any "norms" are based on a 160 pound (more or less) person. If you vary more than 25 per cent from that norm, don't rely on norms at all. Fifth, one drink (12 oz of beer, 4 oz of wine or 1 ounce of liquor, will put max out at creating a concentration of about .02 grams of alcohol for 100 ml of blood in an average metabolic/size person. Sixth, the "average" person eliminates alcohol at the rate of about .015 grams per 100 ml of blood per hour, but there are large variations. Seventh, larger concentrations of alcohol in a person generally slow their metabolic rate, so while 1 drink may be eliminated totally in about an hour and 20 minutes, for two drinks you need three hours, three drinks close to five hours, and so on. Ultimately, for 3 drinks or more, 2 hours per drink is a good "rule of thumb." So, for people of "average size and metabolism" here is a rule of thumb that may be useful, but again, is not universally accurate. For every drink you have, a drink being either 12 oz of beer, 4 oz of wine, or 1 ounce of liquor, wait 2 hours before diving. If you have 3 twelve 12 ounce beers after diving, that means a minimum of 6 hours before getting back in the water. A mixed drink will usually contain from 1.5 to 4 ounces of alcohol depending on the drink type and size, so Know what you have consumed. ALso, most glasses of wine are larger than 4 ounces, so again, know how much you have really consumed. A lot of you can dive safely with a shorter "drinking interval" than suggested here, and have, but I want to be on the safe side. Let's face it, the best beer you ever tasted was one you had after diving. I love a cold beer or two after a day of diving. Later in the evening I might have a single drink. That's my limit if I am diving the next day. But after the last dive on the last day of diving, and I'm not driving or flying the plane home, keep 'em coming! Also, the dive concesionaire's rules trump mine. Know their rules and follow them.
I hope this is useful information to all my fellow divers.
DIvemasterDennis
