I am not sure where to even begin with this. The idea is fundamentally stupid. There is no way to effectively run the ferry service and do any degree of reasonable search of people, cars and trucks as they go onto the ferry.
At an airport the screening is a long process. For plans you need to screen a lot less people and a lot less things. One to two bags per person is all that needs to looked - a total for typical international flight of 300 people and 300 bags
How does any propose to search 300 vehicles and up to 1500 people in anything approaching a reasonable time? Because of the schedule, it would have to be done in the 40 minutes the ferries are loading and unloading. Maybe you could be processing all the time, but that still means no more than one hour to process a full ship load of people and vehicles. The staffing needs of BC Ferries will go through the roof and so will the fares.
Are you going search each car? Very few vehicles crossing between Canada and the US are searched, would the ferries have higher security than the border does?
If one had to be at the ferry one hour early than now, you effectively have changed the round trip ferry time from 4.5 hours to 6.5 hours.
Since the vehicles will have to be there earlier, there will be a lot more vehicles in the terminal parking lots and therefore the parking lots will have to be even larger. This will be ok at Duke Point and Tsawwassen, Swartz bay will have once again blast and rebuild further out, but Horseshoe Bay and Departure Bay have no place to add more vehicles.
The fares have risen rather quickly over the last few years and are high enough now to start deterring people from traveling to and from the island. A few years ago a car and driver could cross to the lower mainland and back for about $60, now it is $100. You can fly from harbour to harbour for $180 to $220 return, a price that has not changed much over the last ten years.
When you fly, you can be from my house to an office in downtown Vancouver in 90 minutes without any difficulties. With the ferry it has taken me about 3.5 hours, with the security check it will add another hour. The plane will save me three hours instead of two and the price difference is only about $50 instead of $70. Before I would had to have earned more than $35 per hour to make the plane worthwhile, with the security check it will drop to $17 per hour.