However, the ferry could be sold out. This almost happened to us. We were two couples. The arriving to the ferry was fine. But it was quite full. There were about five people who were not allowed on the ferry (and since it was the last one for that, that would pretty much ruin your day).

I had not considered that this would be a problem because it was October (very low season). So we didn't buy our tickets ahead of time. I was more worried about not making it on time. Next time I will buy the tickets ahead of time.