Although Crean spent all his lengthy service with the Royal Navy on the lower deck, at crucial times during both the Terra Nova and the Endurance expeditions (click on the links above to find out more about these) he demonstrated strength of character well above and beyond the call of duty and indeed, above which might reasonably be expected of any human being in extremity.
Unlike several of the expeditions' officers, Crean left no diaries, but enough has been written about him and his achievements to for Dooley to have shaped the 70 minute performance. To call it a monologue does an injustice to Dooley's ability to bring Crean to life. Nor was it a lecture, as the dramatic focus was on Crean the Antarctic explorer, dressed in his polar regalia, whose occasional harrowing descriptions of extreme moments were interleaved with lighter elements of self-deprecatory humour.
While it helps to know something of the context of the events (and the program notes give some background detail) I'm sure that many in the audience who didn't have this knowledge were captivated by Dooley's ability to capture the essence of the man. If you get a chance to see a performance, do so.
For reviews of the Edinburgh performance see here, here, here and here.