The effects of an enhanced navigation support information service on maritime traffic risks in the gulf of Finland

The paper presents an Enhanced Navigation Support Information (ENSI) navigation service and estimates how its deployment in the Gulf of Finland would affect the number of ship collisions and groundings. ENSI navigation service transmits the ship's electronic route plan to the Vessel Traffic Service and checks the route. In return, the service sends real-time, route-specific information to the ship such as data on the weather, ice and traffic conditions, the destination and possible disturbances on the route. The service has already been tested onboard Finnish tankers. The tanker safety services will be introduced by 2013 to all oil tankers operating in the Gulf of Finland and can then be expanded to other sea areas as well. According to the maritime traffic accident statistics from the Gulf of Finland, a sea area with increasing tanker traffic and sensitive nature, the primary cause of the majority of accidents has been human failure. Further, 40 % of the human failures had been related to the crew being uncertain of the position of the ship. In this study, the effects of implementing the ENSI service are incorporated into ship-ship collision and grounding causation probability models, and the models are applied to estimating the risk reducing effect for the estimated maritime traffic in the Gulf of Finland in 2015. The effects are modeled probabilistically by eliciting expert knowledge and experiences on testing the service. With the proposed Bayesian approach to modeling the problem, the model can be updated easily and uncertainties in the risk estimates reduced after more evidence is available later from longer and wider use of the service.