Large ships carrying cargo through the Baltic Sea face particular difficulties during harsh winters, so-called hard ice winters, when the entire sea is frozen. Overwide vessels often require the simultaneous use of two icebreakers to open a sufficiently large channel and ships have been stranded for several days waiting for assistance. Faced with growing traffic, northern Baltic Sea countries are at an increasing competitive disadvantage. The EU-funded project 'Innovative icebreaking concepts for winter navigation' (ICEWIN) investigated ways to increase the effectiveness of ice-breaking assistance throughout the Gulf of Finland, largely as related to oil tankers. Analysis focused on the implementation of developed technical solutions as well as the development of new forms of cooperative agreements. A simulation tool developed for the project enabled the inclusion of factors such as increasing traffic, number and condition of vessels, weather conditions and novel agreement scenarios. Scientists found that the current ice-breaking capacity in the Gulf of Finland is not used effectively, and that the existing commercial fleet could play an important role in opening needed waterways. Cooperation among Estonia, Finland and Russia could have major impact in this area. New forms of agreements between countries and fleets could significantly improve the level of service without the need for additional vessels. ICEWIN proposed six new agreement concepts that would have significant impact on ice-breaking operations. For example, daily routes such as those travelled by ferries could be kept open simply by increasing traffic with some form of compensation, thus preventing the routes from freezing over rather than requiring icebreakers when they do. In addition, the schedule of ships could be coordinated such that stronger ships would be followed closely by weaker ones. The implementation of such concepts will require the modification of existing laws and regulations. As demonstrated by the ICEWIN project, coordination among countries will play a vital role in accommodating traffic through the Gulf of Finland during hard ice winters. The mutual benefits are significant, ensuring the economic viability of northern Baltic Sea countries as well as the reliable distribution of oil and manufacture of oil-based products.