You can add a Ferry Voucher when booking your Spaceships campervan. This can be done when making a booking or updating your booking via the Online Check-in Portal.
You then turn your Ferry Voucher into a ferry booking when you're ready to have your ferry ticket issued.
And sometimes, we have a deal that includes the ferry crossing on certain one-way routes. These deals are rare and book out quickly so when you spot one, book it asap otherwise you will miss out.