Aft rigging is a tuning element used to control mast bend and forestay tension to optimise sail shape. Technical committees’ checks on boats have found many issues with aft rigging over the last two years, resulting in boats needing to alter their IRC or ORC certificate. Given both rating systems take these controls into account, it’s only fair that this gets tidied up. 

The first thing to know is that it’s always the owner’s responsibility to ensure their boat complies with its rating certificate. Changes to the aft rigging configuration are often missed when boats have modifications or change hands. If there is any concern, contact an approved measurer and get it checked. 

This diagram is presented to add clarity to the descriptions given in the Equipment Rules of Sailing (ERS). The ERS is basis for all boat, rig and sail measurements. This is the link to the ERS. 

The rating systems ask for different things. IRC asks for information about the number of aft stays, or pairs of stays and backstays. ORC looks at fixed and adjustable backstays, running backstays and checkstays. Fortunately, the ERS and each rating rule carefully describe what each is. It’s just a matter of checking for yourself or consulting a measurer. 

For more about IRC and ORC ratings, click here. 

By Chris Zonca