A boat in New Zealand gets a harder life than almost anywhere else: some of the highest UV levels in the world, salt spray, wet-dry cycles and long winters under a cover. Pick the wrong marine upholstery fabric and it cracks, goes pink with mildew or fades to chalk in two seasons. Here is how the three main options actually behave.
Three materials, three jobs
The confusion starts because people use “marine fabric” to mean everything on the boat. In practice, each material has a lane:
| Material | Best for | Avoid for |
|---|---|---|
| Marine vinyl | Seats, squabs, bolsters, helm pads, cockpit cushions | Covers that must breathe |
| PVC coated fabric | Tonneau covers, dodgers, storage covers, bimini tops in budget builds | Anything you sit on in the sun |
| Solution-dyed acrylic | Biminis, boom covers, full mooring covers, exterior cushions | Bunk squabs (absorbs water) |
Marine vinyl: for anything you sit on
Marine vinyl is a PVC skin bonded to a polyester knit backing, but with a very different recipe from furniture or automotive vinyl. A proper marine grade has three things a domestic vinyl lacks: UV stabilisers in the top coat, anti-microbial agents through the compound to slow mildew, and cold-crack resistance so it stays flexible in a July frost.
Look for a weight of around 750–850 g/m² and a stated UV rating in hours (1,000+ is the usual benchmark). Better vinyls also carry a topcoat that resists sunscreen and denim dye transfer – a real problem on white and cream seats.
Why not just use furniture vinyl?
We get asked this every summer, usually by someone who has already tried it. Furniture vinyl has no UV package and no mould inhibitor. It goes stiff, then cracks along the seams, usually within 18 months. The saving is small and the redo is expensive. Stick to a true marine grade from our vinyl range.
Pair it with the right foam
Vinyl seats are only as good as what’s under them. For open boats and any squab that gets wet, use reticulated (dry-fast) foam that drains rather than holding water like a sponge. Standard seat foam is fine for cabin bunks and enclosed helm seats that stay dry.
PVC coated fabric: tough, waterproof, doesn’t breathe
PVC coated fabrics are a woven polyester scrim with PVC laminated to both sides. They are fully waterproof, very strong on the tear test and cheaper per metre than acrylic. Truck tarpaulin is the same family.
The catch is breathability – there is none. Put a PVC cover over a damp boat for a fortnight and you’ve built a greenhouse for mould. It also gets stiff in the cold and is heavy to handle, which matters if you’re wrestling a full cover off a 6 m runabout at the ramp.
Where PVC earns its place is in covers that see hard wear and don’t need to breathe: outboard covers, tonneau covers on trailer boats, rod holders and cockpit storage. Weld or sew it with UV-treated bonded polyester thread, and use stainless fittings only.
Solution-dyed acrylic: the long-life cover fabric
Solution-dyed acrylic is the material of choice for biminis, boom tents and mooring covers, and for good reason. The colour is added to the acrylic while it’s still liquid, so every fibre is pigment all the way through. That is why it holds colour for 8–10 years in NZ sun when a piece-dyed polyester fades in two.
It is water-resistant (thanks to a fluorocarbon finish, which needs re-proofing every couple of seasons), breathable, mildew-resistant and light enough to fold. Weight is typically around 300 g/m² for cover grades. Our Coastal Outdoor Canvas is a solution-dyed acrylic in cover and cushion weights.
The limits
- It absorbs water in prolonged rain, so it’s wrong for bunk squabs and cockpit seating that stays wet
- Abrasion resistance is lower than PVC – reinforce anywhere it rubs on a rail or windscreen edge
- The proofing wears off; re-treat with a fabric guard spray when water stops beading
Sun, salt and mould: the NZ-specific checks
Whatever you choose, three things decide how long it lasts here:
- UV rating. Ask for it in hours. Under 500 hours is a domestic outdoor fabric; over 1,000 is marine. NZ UV is 40% higher than comparable latitudes in Europe, so a product marketed as “outdoor” overseas may be marginal here.
- Fixings. Salt air eats plated staples in months and the rust stains the vinyl from underneath. Use stainless 71-series staples and stainless or nylon press studs.
- Ventilation. Mould needs still, damp air. A cover with vents, a squab with drainage foam and a cabin left cracked open will outlast a sealed one every time.
Fire ratings and survey boats
If your vessel is in survey – charter, commercial fishing, passenger – the upholstery must meet the relevant fire performance requirements, and the operator’s Maritime NZ safety system will specify what documentation is needed. Our guide to NZ fire ratings for marine fabrics covers AS/NZS 1530.3 and AS/NZS 3837 in detail. For a recreational trailer boat, no rating is required, but a low-smoke vinyl is still a sensible choice in an enclosed cabin.
Looking after it
Rinse vinyl and acrylic with fresh water after every salty trip and let them dry before the cover goes on. Clean with a mild soap – never a solvent or an abrasive cream, which strips the UV topcoat off vinyl. A vinyl protectant with UV blockers twice a season roughly doubles the life of white and cream seats. Store cushions upright in the cabin, not flat on the cockpit floor, so the reticulated foam can drain.
Ordering the right amount
Marine vinyl is typically 137 cm wide, PVC and acrylic 150–200 cm. A pair of runabout back-to-back seats uses roughly 3–4 m of vinyl; a full set of squabs for a 6 m cabin boat is closer to 8–10 m. Covers vary hugely with the pattern – measure the longest and widest points, add 15% for seams and hems, and send us the numbers through the contact page for a check before you buy.
DIY or trade?
Recovering a flat squab is a satisfying weekend job. A full bimini with bows, zips and clear windows, or a helm seat with compound curves, is another matter – it needs a walking-foot machine and a lot of patterning. If you’re in Auckland, our sister business Upholstery World does marine upholstery on-site at the marina or your driveway, and can work with material you’ve chosen from us.
Shop it: Marine vinyl, PVC coated fabric and solution-dyed acrylic are all in our outdoor & marine range, with reticulated foam cut to size in foam & padding. Order a swatch first – colour on a screen and colour on the water are two different things. Everything ships nationwide from our workshop — courier to any New Zealand address, or click & collect.