Most flag states require a tonnage measurement survey for vessels under 24m in load line length before registration. Vessels over 24m in load line length are required to have an International Tonnage Certificate (ITC69) and Certificate of Survey (CoS) issued by an approved classification society.
Under Merchant Shipping Laws, yachts registered under the Red Ensign Group (REG) must undergo a tonnage measurement survey by a recognized surveying authority or classification society before registration.
Many well-regarded non-British flag states, such as Malta, also require a tonnage measurement or similar pre-inspection survey before initial registration.
The tonnage measurement certificate provides:
- The yacht’s official tonnage, dimensions, and mechanical specifications
- Information for the Certificate of Registry
- The basis for safety regulations, manning requirements, and operational fees (such as mooring and harbor fees)