Sweden relies on shipping for trade and supplies. But how would shipping be affected by conflicts and war? Are there enough Swedish-flagged ships? What kind of protection would the merchant fleet need? How does war insurance work? This report explores the meaning of economic defence in the maritime domain, a subject that concerns many areas, including industry policy, transportation, insurance and naval defence.Considering that the conditions of shipping in war has not been a central policy focus in recent years, the report argues that there is now a need to create more coherent strategic thinking about maritime issues, conjoining civil and military preparedness. The report analyses conditions regarding, among other issues, trade, insurance, flagging of ships and maritime workforce. A general conclusion is that the deteriorated security context of the Baltic Sea has underlined the need to take action to strengthen Sweden's blue, i.e. seadependent, supply preparedness.