Interview went fine (very nice to speak to the technical manager) I was told the next day that the interview was successful and to pay for my Visa (to be refunded when onboard ship) and my Criminal Background Check (a total of £155). I was then told that I'd be informed when a vacancy became available. No-one, at any point, had mentioned that I wasn't applying for a current vacancy.
Staff at the agency were inconsistent with information, and consistently rude with me when I emailed or called.
How things were left were that the agency would inform me when the vacancy became available. At the point at which I'm writing this it has been well over a year since my interview.
I cannot warn you against DCL highly enough. Even if the agency you go through tells you to have your medical, get your visa, and have a CBC conducted: don't unless you have a contract/start date.