[KeelHaulin]

Originally Posted by JimHawkins

Here's the link to Sector Honolulu Inspection Note #13.
It says replace wire every 6 years, fittings every 12 years, and chainplates every 18 yrs. It also says to visually inspect regularly and replace any defects found, but it doesn't say what regularly is.

That's within the context of a chartering multi-hull. Please read the following:

Originally Posted by USCG Sector Honolulu

DEFINING THE PROBLEM. Hawaii’s small passenger sailing vessel fleet is comprised of 95% multi-hull vessels that operate in more extreme wind and sea conditions than experienced by the national inspected sailing fleet, often with passenger loads at or close to the vessels’ capacities. The inherent high initial stability of multihulls due to their beam and the resulting stiffness of the hull, especially when fully loaded, translate more force directly to the rig compared to similar sized monohulls that roll out (heel over) as wind pressure increases. This combination of unique sailing design and a high wind operating environment make regular inspection of key components critical to good preventive maintenance.

But to answer your question; you should visually check your rigging at the deck level before each sail, and go up the mast at least twice per season to visually inspect the shroud attachments and tangs. On wire the most common failure is where it enters the swage, individual strands will begin to break as they reach their fatigue limit. There are other forms of failure (like cracking of the swage) but strand failure the most common. Rod rigging is more difficult to inspect and usually just requires complete replacement at ~20 years of service because proper x-ray inspection is not cost effective for rigging that is nearing the end of it's service life. It is not maintenance free; the heads should be regularly inspected for crevice corrosion (see navtec website for more info).