Totally agree with wrjordan as far as 'irregularities' are concerned but scanners can be engineered that maintain a defined standoff. That is if the deck were fairly consistent and mostly free of obstructions – aircraft carriers and the like. I understand that there’s a few in China now?
Hand spraying large deck/ground areas isn't great for your vertebrae.
I recommend an ultra long reach push/pull system that doesn’t spit/misbehave in any orientation or position. We have the perfect/ideal systems.