Conversely, open registries frequently offer on-line registration with few questions asked.
The use of flags of convenience lowers registration and maintenance costs, which in turn reduces overall transportation costs.
In 2011, Cunard Cruise line registered all its ships in Bermuda, which, besides other considerations, enabled its ship captains to marry couples at sea, weddings at sea being described as a lucrative market., thirteen flag states have been found by international shipping organizations to have substandard regulations.
On the other hand, maritime industry practitioners and seafarers from other countries contend that this is a natural product of globalisation.
Registries may be governmental or private agencies.
The reasons for choosing an open register are varied and include tax avoidance, National or closed registries typically require a ship be owned and constructed by national interests, and at least partially crewed by its citizens.
The accumulated advantages can be significant, for example in 1999, 28 of the American company Sea Land's fleet of 63 ships were foreign-flagged, saving the company up to US.5 million per ship every year.
Under port state control, ships in international trade became subject to inspection by the states they visit.
As of 2009, more than half of the world’s merchant ships were registered with open registries, and almost 40% of the entire world fleet, in terms of deadweight tonnage, were registered in Panama, Liberia, and the Marshall Islands.
A ship's flag state exercises regulatory control over the vessel and is required to inspect it regularly, certify the ship's equipment and crew, and issue safety and pollution prevention documents.
The organization which actually registers the ship is known as its registry.
and a ship is subject to the laws of that country, which are used also if the ship is involved in a case under admiralty law.
A ship's owners may elect to register a ship in a foreign country which enables it to avoid the regulations of the owners’ country which may, for example, have stricter safety standards.
New Part 1 (Commercial) and Part 4 (Bareboat) application and registration process for merchant ships, including workboats, tugs, large cargo ships and passenger vessels operating commercially on the UK Ship Register.