Where you check-in for your ferry will be different for each operator and port. You can find information on where to check-in on the port pages and in your confirmation email. We do our best to keep this information up to date, but it can change at short notice, so it's essential to give yourself plenty of time to check-in. You'll find the final check-in time in your confirmation email.
You can find the address to the port in your confirmation email, as well as a link to Google Maps, to help with directions.
You can also look at the port page to find more details about the port and the address. Some ports can be pretty big, with different addresses for different ferry companies, so make sure to check that you have the correct address for your ferry.