The Vigilant is an overlord-class battlecruiser, and serves as Battlefleet Achernar's flagship. It is normally stationed at Kaprun to safeguard the shipyards, but is deployed when Admiral Tryphosa leads the fleet against substantial threats. Given the rarity of its deployment, its crew are well-drilled but untested, as a full fleet deployment tends to happen only once in a generation. To mitigate this problem, Tryphosa has been known to treat the Vigilant as a "retirement home" for old sailors with combat experience, and seeds these knowledgeable types among the untested crew. The advantage for the veterans is that they effectively have a job that keeps them safe and docked around a comfortable colony with frequent shore leave.
The Vigilant's captain is Aldous Montague. He has mentored so many of Battlefleet Achernar's officers, including Admiral Tryphosa, that he is seen as a paternal figure. It is said that the Vigilant's crew spend much of their extensive downtime trying to guess his age. Advanced in years and the subject of a great many romantic portrayals of navy life, the triple amputee is said to be both fearless and unkillable. Those who have actually met him say he now runs more on tired habit, and has only avoided retirement because he'd have no idea what to do with himself without the routine of life aboard a ship. In this regard, Montague is cut from much the same cloth as the other old sailors aboard the Vigilant.