Coincidentally, while doing a bit of factual research prior to posting a further photograph here, I came across a P&O fan website and discovered an unauthorised copy of my Shipspotting picture of the Oriana. I was not best pleased. I have refreshed my view on photo copyrights and came across this document. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/481194/c-notice-201401.pdf
Interestingly, in your case, it refers to the copyright of photos of copyrighted objects. An example given was a photo of an art gallery where many copyrighted objects would be on display. In that regard, the photo of the copyrighted objects is seen as being incidental to the photograph and not subject to those copyrights. So it could be suggested that unless a photo of a ship focused specifically on the name or livery but instead related to the form of the ship and its environment, the copyrighted aspects of the vessel were incidental to the photograph and did not apply.