I have found AFerry very useful in the past for comparing and purchasing tickets for ferry crossings. Today having booked 2 ferry crossings I went, out of interest, to the site of the company involved and found the same crossings were cheaper. Additionally the Aferry charge for a credit card is high and the charge for a debit card is ridiculous.
So use the AFerrysite for getting information but check the site of the company you are going to use and buy there.
Connect with Facebook to get one click access to Trustpilot. It's easier.Sign up with Facebook