Concern with safety in particular has resulted in efforts to phase out open registry of ships. This study employs a transcendental logarithmic framework to highlight some of the cost implications of adopting such a policy in terms of the higher shipping costs which would result. It compares the cost functions of open registry ships with those of ships registered under traditional maritime nations in order to offer some insights into the possible impacts on shipping markets of withdrawing the opportunities for shippers to elect for open registration.