In this paper a numerical model and experimental data are applied to investigate and analyze the level ice performance of a double acting intervention vessel. This includes both ice-breaking capability and maneuverability aspects where h-v curves, breaking pattern, and turning circles are evaluated and discussed. As part of the study a static dynamic positioning capability analysis is carried out to evaluate the vessel's stationkeeping performance in ice. The analysis is based on a heading prioritized thrust allocation algorithm and the simulated ice loads acquired by numerical towing experiments. The preliminary results include, what we call, DP-Ice Capability Plots, which are parameterized by ice thickness and drift speed.