Boat plug question?

This may be a dumb question but I would rather find out now then 10 mins after the baot is in the water.

We have just picked up a 1990 MAstercraft MAristar. Put he monster tower on it, put the perfect pass onit. brought it home put it in my dads driveway , he starts looking at the boat ( he is a big boat guy 46' or bigger is his kind of boat) and he asks" where is the plug?" Of course I am dumbfounded and unable to answer. My wife looks at me and just shakes her head.

We start looking all over for it and are unable to locate it. So now I have to figure out where it is located before it goes in the water. Can any one help me locate it? It would help me regain some( a shred) of my dignity in front of my wife. I would appreciate it.