Isthmus Bureau of Shipping, also known as ClassIBS, is a ship classification society.  The principal work of the Society’s expert technical staff is to undertake surveys to ensure that the rules that apply to new construction and existing ships are followed, in order to ensure the safety of these vessels and the prevention of marine pollution.

In addition to its classification activities,ClassIBS conducts surveys on behalf of third parties including State Administrations, and verifies the safety management systems of ship-management companies and ships, in accordance with the International Safety Management (ISM) Code and International Ship and Port Facility Security (ISPS) Code.