This article provides an insight into some aspects of the possessory lien in admiralty actions in rem. In particular, the article discusses the authority of a demise charterer to subject the chartered vessel to a ship-repairer's lien and to what extent, if at all, this authority is affected by the presence of "non-lien" clauses in demise charterparties. The matter of what constitutes the res subject to the possessory lien of the ship-repairer is also examined.