Independent guide: Catamaran rigs vary widely between builders. Use this page to understand the system, then confirm details with your builder's documentation and a rigger.
Quick answer
A cruising catamaran's rig is usually a deck-stepped fractional or near-masthead sloop with swept-back spreaders, no backstay and a forestay attached to a bridle or crossbeam. Because a catamaran barely heels, gusts load the rig directly, so shrouds, chainplates, the bridle and the mast compression post work hard. Priority services are forestay and bridle inspection, chainplate checks in the hulls, compression-post and mast-step inspection, and care of the large mainsail's halyard, lazy-bag and reefing system.
How a catamaran rig differs from a monohull
| Feature | Catamaran | Typical monohull |
|---|---|---|
| Mast step | On deck, over a compression post or beam | Keel-stepped or deck-stepped |
| Forestay attachment | Bridle to both bows, or a crossbeam | Stemhead fitting |
| Backstay | Usually none | Usually yes |
| Shroud base | Very wide | Narrower |
| Heeling | Minimal — loads go into the rig | Heels and spills gusts |
| Mainsail | Large, square-top or high-roach | Smaller relative to boat |
| Reefing | Heavy slab-reefing systems, long line runs | Varies |
What to inspect on a catamaran rig
Forestay and bridle
The forestay may be inside a furler and attach to a bridle apex plate or to a beam. Inspect bridle wires or Dyneema for chafe, the apex fitting, the terminals and the bow attachment points. A bridle failure loads the forestay unevenly and can bring down the rig.
Shrouds and chainplates
With no backstay, the shrouds — swept aft — support the mast fore-and-aft as well as sideways. Chainplates are often bonded into the hull sides or bulkheads and can leak into cored structures. See chainplate replacement.
Compression post and mast step
The mast sits on the bridge deck above a compression post or bulkhead, often in the saloon. Look for cracking in the deck around the step, movement, water staining, and doors that stick in the bulkhead below — all signs of compression-structure problems.
Mainsail systems
Catamaran mainsails are big. Halyards are often 2:1, with a heavy headboard car on a track. Check the car and track, halyard lock or 2:1 block, reefing lines, lazy-jacks and stack pack. Many catamarans lead everything to a winch at the helm, so line runs and turning blocks see high friction and wear. See running rigging replacement.
Downwind and light-air sails
Code zeros and gennakers on a bowsprit or the forward beam need their own tack fittings and halyards; check the beam attachment and bobstay.
Services catamaran owners most often need
- Complete re-rig, usually mast-out, at around ten years or on purchase
- Furler service and forestay inspection
- Chainplate inspection and re-bedding
- Running rigging replacement, particularly main halyard and reefing lines
- Mast stepping with a crane large enough for a tall, heavy mast
- Rig modifications such as Dyneema bridles or code-zero furlers
Australian conditions
Catamarans are extremely popular in Queensland — from Moreton Bay and the Gold Coast to the Whitsundays and Cairns — and in charter fleets. Tropical UV breaks down synthetics, bridle covers and sail covers faster, and warm salt water accelerates crevice corrosion in stainless terminals. Cyclone season adds a preparation step; see cyclone preparation for rigging.
Popular catamaran brands
- Lagoon catamaran rigging
- Leopard catamaran rigging
- Fountaine Pajot catamaran rigging
- Seawind catamaran rigging
Costs
Frequently asked questions
Why is catamaran rigging under such high load?
A catamaran is very stiff because its two hulls resist heeling, so gusts are not spilled by the boat leaning over. Instead the load goes straight into the rig. Combined with wide shroud bases, large mainsails and no backstay on most designs, this means shrouds, the forestay bridle and chainplates carry high loads.
What is a catamaran forestay bridle?
On many catamarans the forestay attaches to a bridle — two wires or Dyneema lines running from the forestay's lower end to each bow — or to a crossbeam between the hulls. The bridle, its terminals and the bow attachment points are high-load components that should be inspected as carefully as the forestay itself.
How much does it cost to re-rig a catamaran in Australia?
Catamaran re-rigs generally cost more than a monohull of the same length because masts are taller, wire is larger and the lift needs a bigger crane. See the catamaran re-rig cost page for indicative planning bands, and get an itemised quote for your boat.
Do catamarans need a backstay?
Most cruising catamarans have no backstay because the mainsail roach would foul it. Instead the mast is held by swept-back shrouds and often diamond stays or runners on performance designs. That makes shroud condition, spreader sweep and chainplate integrity especially important.