It was hours of stress ferry passenger Sue Maclean says could have been avoided.

She and her boyfriend spent the long weekend camping in Tofino, B.C., and headed home to Vancouver on Monday — gunning for the last ferry out of Nanaimo's Departure Bay.

But at 7:30 p.m. — two hours before the sailing — highway signs and the BC Ferries website already said the vessel was 100 per cent full.

"We started to get very stressed out," said Maclean, thinking they'd need a hotel for the night and would miss work the next day.

They kept driving, rolling into Nanaimo's Departure Bay terminal hoping to squeak on the boat and were met by a flagger who said they might have a better shot in Victoria — a two hour drive away.

Still, they took their chances and got on the 9:30 p.m. sailing — only to find the boat leaving with room for dozens more cars.

"It just created so much undue stress," said Maclean.

"How many people ruined their nights and didn't get home due to false information?"

Ferry employees told passenger Sue Maclean that another 65 or 70 cars could have fit on the vessel. No one was left waiting at the terminal, but Maclean wonders how many turned away, assuming it was futile. (Susan Maclean)

Reservations unclaimed

BC Ferries says it gives passengers "the best information available" at the time, and the late sailing was completely booked earlier in the day.

What changed is that people made reservations they didn't cancel or show up to claim, said BC Ferries spokeswoman Deborah Marshall.

"If customers choose not to use their reservations then don't contact us, then we're not able to free that space up in the system until 30 minutes before."

(Reservations, which cost $10-$21 on the route, must be claimed 30 minutes before the sailing time or they won't be honoured.)

The Queen of Oak Bay is one of several vessels that carried passengers between Departure Bay and Horseshoe Bay this long weekend. (BC Ferries)

That's how a sailing like Maclean's could have 100 per cent of its deck space committed earlier in the day — and be only 70 per cent full after reservations expire.

"It said hours in advance, that it was at 100 per cent capacity. There's no way you're getting on," said Maclean.

"Then, at 9 o'clock, we checked it again, and, lo and behold, there's 30 per cent of the space available."

How much of a vessel can be reserved varies by route and terminal, but from Departure Bay to Horseshoe Bay, about 40 per cent of the deck space can be booked in advance, Marshall said.

BC Ferries said it would help if travellers planning not to use their non-refundable reservations would cancel them.

Maclean was told to try driving to Swartz Bay in Victoria when the Departure Bay sailings appeared full, but they decided to chance it and got on the Nanaimo boat. (Deborah Goble/CBC)

No one left behind, says BC Ferries

The long weekend, of course, is very busy for BC Ferries, and traffic heading to the mainland started backing up at Departure Bay mid-afternoon on Monday.

At around 3:30 p.m., more than 650 cars were waiting that wouldn't make it on the next sailing, said Marshall.

Even by the second-to-last sailing, at 9:05 p.m., more than 200 cars were left waiting.

But by the last sailing, which Maclean got on, everyone who was waiting made it on the boat, said Marshall.

"That did take all the vehicles that were in the lot; it did have some extra space on it."

Maclean said employees on board told her there was room for another 65 or 70 cars.

She wonders how many people turned around and gave up before reaching the terminal, assuming it was futile.

"There were so many more people that could have gotten on that ferry."

She is planning to travel again on Labour Day — and has already made her reservations.