Abstract: A method is presented for simulating marine assets (MA) in an offshore operation. The marine assets comprise at least an anchor, a line coupling the anchor with a winch, and a support platform located offshore for supporting the winch. The method involves a computation stage for estimating a state of the marine assets using a computational model and received sensor data (Ds) pertaining to a state of the marine assets and/or of an environment (ME) wherein the marine assets are used. The computational model of the marine assets (MA) includes at least a specification of an anchor, a specification of a winch and a specification of a line coupling the anchor with the winch. The at least a line is modeled as a first portion extending between the winch and a touch-down point where the line touches the seabed and a second portion extending between the touch-down point and the anchor.