The Codes of Practice require all coded vessels comply with certain stability requirements. These criteria and standards will depend on the vessel design, the specific Code of Practice, and the nature of your boat’s operations.

The YDSA Certifying Authority will review the evidence of stability to satisfy itself the relevant stability criteria have been met. This evidence generally takes one of two forms: a Stability Information Booklet or a Simplified Assessment of Stability.

Stability Information Booklet

These are generally required in the following situations:

• Vessels operating in Area Category 0 or 1
• Vessels carrying 16 or more persons
• Vessels carrying cargo greater than 1000kg
• Vessels fitted with a lifting device
• Vessels engaged in towing
• Pilot boats
• Sailing Catamarans

There are other situations where a Stability Information Booklet is required by the Code of Practice. It is important you discuss your Stability requirements with your Nominated Coding Surveyor.

Stability Information Booklets are large technical documents that take time to examine so we can be satisfied the vessel meets the relevant stability requirements. If stability documentation is not presented in an approved format, the checking of the booklets will take longer and additional fees may be charged.

Details of the stability fees due to the YDSA Certifying Authority are listed in the Fees section below and will be either: Intact Stability, Damaged Stability or Sailing Multihulls.

If you do not already have a Stability Information Booklet but require one, talk to your Nominated Coding Surveyor or take a look at our Find a Designer option to see who can help.

Simplified Assessment of Stability

If the vessel does not require a Stability Information Booklet, it will require some form of Simplified Assessment of Stability. What is required depends on the vessel design, the specific Code of Practice, and the nature of your boat’s operations. This can usually be overseen by your Nominated Coding Surveyor but may require additional information or documentation, so it is important you discuss your stability requirements with them.

Details of the stability fees due to the YDSA Certifying Authority are listed in the Fees section below and under Issue of Stability Category.

Modifications and Repairs to the Vessel

Any changes that alter the vessel from the original design may impact on the stability of the vessel. For example, the addition of a mast-furled main sail or a radar antenna may cause the vertical centre of gravity to be at a higher level than that intended by the designer which will impact the stability of the vessel.

The YDSA Certifying Authority must be notified of any repairs or modifications that change the vessel from the original design so we can decide what action, if any, is required.