As I mentioned in the other thread, there is always enough to go round. Let's say you are in a 50 man mess and each man is entitled to two tins per day. That means there are 100 tins to go round. Take off all the men on watch or those trying to snooze before going on watch and you have around 25 people who might fancy a drink, then take off the recovering alcoholics who don't drink at sea and you will probably have closer to 20 blokes per night who actually want to drink, by my calculations this means it is more like 5 beers per man before you even consider the buckshee booze that is stashed away, this is made up of left over tins from previous issues that are hidden away from the Joss man.
As previously stated, there are heavy punishments for drinking more than your daily ration and if you draw attention to yourself and mess by acting the twat, you can end up getting your entire mess on a beer ban, which will make you well popular.