Short answer

Inspect chainplates above deck for cracking, rust bleeding, elongated pin holes and movement under load, and below deck for water staining, softened core, corroded fasteners and damage to the backing structure. Chainplates that pass through the deck are exposed to crevice corrosion where they are least visible, at and just below the deck line.

A chainplate transfers stay or shroud load into the hull structure. The wire above it can be perfectly sound while the chainplate is the weakest link — which is why a re-rig does not automatically address chainplates.

The dangerous zone is the deck penetration. Stainless steel corrodes aggressively in low-oxygen conditions, and a chainplate sitting in a damp, sealed slot is exactly that environment. Damage there is hidden by the very sealant meant to protect it.

Below deck matters as much as above. Follow the chainplate to its attachment and look for staining, rust weeping from fasteners, crushed or softened core around bolts, cracked tabbing, and any sign the bulkhead or knee is working under load.

Deck leaks near a chainplate are never cosmetic. Water entering there attacks both the fitting and the structure it is bolted to. Full detail is in the chainplates guide.

Step by step

  1. Clean and look above deck

    Remove salt and old sealant smears. Check for hairline cracking around the pin hole and at the shoulder.

  2. Check hole geometry

    A round hole that has become oval indicates wear and load beyond design. Measure rather than eyeball it.

  3. Look for rust bleeding

    Rust weeping from under a fitting or a fastener means corrosion where you cannot see it.

  4. Go below

    Inspect the underside, the fasteners, the backing plate and the surrounding bulkhead or knee for staining and movement.

  5. Load test by observation

    With the rig loaded on one tack, look for movement, creaking or sealant working at the deck penetration.

  6. Escalate to removal

    Any doubt means removal and inspection of the buried section — the only way to clear a chainplate properly.

Key facts

Highest-risk location
At and just below the deck penetration
Warning signs
Rust bleeding, elongated pin hole, cracking, deck leak, movement under load
Included in a re-rig
Not automatically — chainplates are usually a separate scope item
Definitive check
Removal, clean and inspection of the full length

Full background: read the guide