Originally Posted by mmwjr
Sounds like the draft with the drive up not down.
You're probably right. The spec didn't specify. It' a 19 ft runabout. I doubt it will be 3.5' either. Splitting the difference will get you within inches, most likely.
As mentioned, measuring in the water will be the best way. The other thing to consider is that if there is a boot stripe of some kind it will be above water, as will the swim platform. That should get you within inches as well.
If the difference between floating through and touching bottom is 6 inches, it's already too close in my opinion.