Ferry tickets are always nominative and you are required to give some personal details in order to issue them: full name, gender, nationality, date of birth, etc. The booking systems of ferry companies typically offer only "male" or "female" options for gender, with no other choices available.
Gender is a significant factor only for "shared cabins," where passengers are assigned to cabins based on gender. On domestic routes, if you book a bed in a shared cabin with the wrong gender, correcting this is mandatory to ensure you can board and use the cabin as intended. For all other types of seating or accommodations, gender is not a consideration, and mistakes in gender details are unlikely to cause issues.
For international travel, we strongly recommend contacting either us or the ferry company to confirm if any correction is needed.