Stainless wire looks the same at 15 years as at five, then fails at a terminal. That's why age matters for standing rigging in a way it doesn't for much else on a boat. Insurers ask, riggers have a number, and the surveyor reports what the evidence shows.
What the industry expects
Yachting Monthly sums it up: insurers generally recommend replacing standing rigging every 10 years, and most riggers agree this is a reasonable life expectancy. It suggests a professional rig inspection every three years. For rod, it notes a shorter lifespan and no warning of failure.
Policies vary, so the insurer's own wording is what applies to a given boat.
How a surveyor checks it
Start with the paperwork: when was the rig replaced, by whom, and is there an invoice. Then look. Run an eye along each wire for broken strands and rust, and look hard at each terminal, where most failures start. Practical Sailor's line: any swage fitting that is cracked should be replaced. Check turnbuckles, toggles and chainplates.
From deck level you see the bottom terminals. The top ones need someone aloft or the mast down, and the report says which were seen.
What decides the grade
Defects first, then age. Broken strands or a cracked terminal is an A. Wire past about 10 years, or of unknown age, is a B. Rigging within its life with no recent rig check is a C.