There are a lot of ships out there flying the Liberian flag. But that’s not to say the Liberian shipping industry is well developed. Rather, foreign owners of merchant ships register their ship in Liberia (a sovereign state different from that of their own), and fly Liberia’s flag on their ship.
This practice is known as “flag of convenience,” because the ship operates under the laws and regulations of its “flag state,” which are more lax, and therefore reduce the operating cost for the ship owners. For example, the ship owners follow the labour and environmental regulations of the flag state, and avoid the taxes, restrictions, and standards of their own countries (which is why the practice has drawn criticism from labour unions, environmental groups, and others).
The profit-oriented ship owners are happy, but so is Liberia, because the government gets a steady revenue stream from ship registration fees. Liberia is one of the world’s largest ship registries in terms of deadweight tonnage, second only to Panama. It is estimated that some 3,500 ships fly the Liberian flag, with a weight of 113 million gross tons (over 10% of the world’s ocean going fleet).