An in rem endorsement is a workers compensation coverage endorsement extending coverage for suits filed against the value of the ship by an injured crew member seeking for the recovery of damages.
The suit must cite the unseaworthy condition of the vessel as proximate cause of the damages. In the absence of this endorsement, an in rem suit could result in an injunction preventing the vessel from leaving port until the suit is settled. In rem coverage is now part of the maritime coverage endorsement rather than a separate endorsement.