A "yacht" refers to a method of ingesting marijuana. This method involves using a bong or water pipe, with a regular bowl. After packing 1/3-1/2 of a cigarette into the bowl the top must be covered with green. Once the top is completely covered with green it is smoked all in one hit. This method provides more than a considerable headrush, creating the feeling of light-headed-ness or nausea. The side effects could be occasionally puking.
This method could be considered bad, as you are smoking half of a cigarette + marijuana. But after doing the math to this I have drawn a very positive conclusion: 3 a day = 1095, 1095/2 = 547.5, This is 547.5 cigarettes a year. (this method is great to quit smoking) and 1095 marijuana hits a year. The avg. smoker smokes 7300 cigarettes (assuming 20 smokes a day) The Avg. pot smoker smokes over 5000 hits of marijuana a year.
This method of smoking marijuana removes the need to smoke otherwise, and removes the need to smoke marijuana otherwise.
So in technical terms, this method could save you 6752.5 cigarettes a year and around 3905 hits of marijuana. This is assuming that you do not use any other methods of smoking and do not smoke cigarettes.