It is well known that the transition from the Ancien Régime to the Late Modern period had a significant impact on the system of punishments. Precisely in this historical phase - between the 18th and 19th Centuries - the mechanisms of punishment began, in fact, to move from a physical dimension to a more properly custodial one. In this sense, the punishment of forced labour was paradigmatic: an essentially prison-like penalty but linked to the hard labour of the prisoners who, in the Italian criminal law system, was expiated inside the so-called «Bagni penali» (maritime penal colonies), detention and labour facilities which took this name because of their usual location in coastal places and, more precisely, near ports and maritime military arsenals. In these prisons, which were under the administration of the Navy, religious assistance to the condemned was provided by Navy chaplains. In such contexts, characterized by a permanent emergency condition, the spiritual care of the condemned to forced labour assumed a fundamental role not only in ensuring religious practice, but also as a crucial aggregation factor. This presentation aims to focus, from a comparative legal-historical perspective, the events that concerned the spiritual assistance of the condemned in the so-called «Bagni penali» during the Ninenteenth Century, having regard to three different contexts: the Kingdom of the Two Sicilies, the Kingdom of Sardinia and, finally, the Kingdom of Italy where, after a progressive process of demilitarization, the «Bagni penali» were definitively abolished in 1891.