I was amused to find a reference to Gore Vidal in O'Brian's "The Wine-Dark Sea" on p.157. A midshipman or petty officer named Vidal is described as chapelist, democratic or even republican in his views, in other words a left-winger, that is, for early 19th century England. There the resemblance begins and, perhaps, ends. This Vidal conspires to free an imprisoned Frenchman by the name of Dutourd, who seems to be a pacifist that wants to start a democratic, money-optional commune on a deserted island. The reference may pass unnoticed by anyone that hasn't read Gore Vidal. At first I wondered whether O'Brian intended a mild rebuke of Gore Vidal's political views, but upon reflection I think the author just meant to tip his cap to a fellow historical novelist. I can't assume that O'Brian's views were that much different than Gore Vidal's, other than on the subject of homosexuality, where O'Brian had difficulty.
Gore Vidal's literary criticism is remarkable in its profound silence upon O'Brian. I only found one sentence indicating Gore Vidal was even aware of O'Brian. I think Gore may have found O'Brian too abundant with minute facts and technical details, too objective, and lacking that strong point of view which Gore always invested in his own work. Gore had a profound distaste for war and did not like to read or write portrayals of war. By contrast, O'Brian's books drip with blood and gore.