What is the difference between a 'baffled' and an 'unbaffled' (smooth bore) tank?

Baffled tanks have interior walls with holes (or 'baffles') that limit the rapid movement of liquid front-to-back. They reduce the most violent surge effects, making braking and acceleration more predictable. Unbaffled or 'smooth bore' tanks have no interior partitions. They are common for food-grade products (milk, water) and certain chemicals where baffles would create cleaning or contamination problems. Driving a smooth-bore tank requires much more skill and caution because every stop and start triggers significant surge. Tank type matters because the same driving inputs that are safe in a baffled tank can shove a smooth-bore vehicle through an intersection or roll it on an off-ramp. Always know which type of tank you are driving.