There was a recent letter in the CAMC magazine about someone being charged £50 for entering the relatively new Clean Air Zone on the way to the Portsmouth Ferry Port. I live near Portsmouth and just checked with the Council. If you are going directly to the Continental Ferry Port and come down the M275 and get off at the roundabout and go directly into the Ferry Port, there is no charge. If you are going to the Isle of Wight Ferry, you would being entering the Zone and would be charged. If you go into the city for a visit and then go to the Port, you would be charged. There are no charges for "private vehicles", so I guess it depends on the size of your van and what your designation is. But £50 each way is a huge addition to the cost of the passage, so it is worth checking out before you plan your journey.