Greg: You were wise to drain your tanks. That is the recommended practice which, to my detriment, I did not follow. When I shipped 5 years ago the tanks were original 1976 models, they were full, and one split a seam on the way across. Forty gallons of diesel sloshing back and forth from stem to stern under the sole is no joke. This time the tanks were brand new, they weren't anywhere near full so I didn't drain --- no issues but I should still have followed protocol.
By the way, hauling via semitrailer should run around $5 per loaded mile at the current price of diesel and bearing in mind the fact that the route is probably going to be less than direct because of width restrictions. If the price of diesel goes up a dollar a gallon, that should not add more than 20 cents per mile to the cost. If you can find a haul at $4 you have a real bargain. If it's much over $5 you're being stung.