I don't know about the Corpy uniform - I have an unidentified photo of early 20th c of a group of men in uniform of some form that neither I nor the museum can identify but almost certainly local to Douglas.

It's not the Steam Packet Prince of Wales is it ? as the IoMSPCo laid up many of its vessels over winter often in various UK ports and especially if work was needed on them - they would have a skeleton crew who lived on board over the 6 months period