Ask ten superyacht captains "inflatable or foam?" and you'll get ten different answers, but the framing itself is wrong. The marine industry talks about fenders in two categories when there are really three, and most of the confusion in owner conversations comes from the mix-up.
What gets called a "foam fender" is almost always a Polyform A-series or F-series, or an equivalent Taylor Made, Plastimo, or Castro product. None are foam-filled. They're air-inflated rotomoulded PVC, with a valve and roughly 2 psi internal pressure. True solid-foam fenders exist but are a separate niche product: Hauraki Hurricane, Xquip, dedicated transom and dock fenders. Modern welded-seam textile inflatables from SEARAFT and Fendequip are a third category again. This guide untangles the three, with honest comparisons on weight, storage, lifespan, and cost.
The three-category reality at a glance
Polyform A-series and F-series are air-inflated rotomoulded vinyl, not solid foam, despite the popular "foam fender" label. True solid-foam fenders use a closed-cell EVA or polyurethane core and are a third, niche category, mostly used for transom, swim-platform, and commercial dock work. Welded-seam textile inflatables (SEARAFT, Fendequip) are the modern superyacht standard.
The three construction categories
Most published "foam vs inflatable" comparisons collapse two distinct products into one column. Splitting them out makes the rest of the decision cleaner.
1. Air-inflated rotomoulded vinyl
What most people picture when they say "yacht fender." Rigid-feeling PVC shell, ribbed end caps, valve on top. Rotational-moulded one-piece bodies with no seams to fail. Examples: Polyform A and F-series, Taylor Made Big B and Super Gard, Plastimo, Majoni, Castro. Around 2 psi. White, blue, red, or black direct from the mould.
2. Solid foam-filled
Closed-cell EVA or polyurethane foam core wrapped in a thick polyethylene or polyurethane skin. No valve, no air cavity, no possibility of deflation. Examples: Hauraki Hurricane (NZ), Xquip, Fendequip's transom and dock range. Mostly used for transom and swim-platform protection, commercial dock work, and permanent piling installations where unsinkable, install-and-forget behaviour matters more than packability.
3. Welded-seam textile inflatables
The modern superyacht standard. Heavy-duty PVC, polyurethane, or Hypalon-coated fabric welded into a low-pressure cylinder or sphere that runs at around 1 psi. Examples: SEARAFT, Fendequip maxiStow, AERÉ, Defenda, Ocean Magnus. Custom sizes to 270 cm, custom covers, full deflation for transit. Covered in detail in the pillar guide and the dropstitch vs welded-seam comparison.
Three separate products with three separate use cases, not a binary choice.
Polyform: heritage and the "foam fender" myth
The Polyform story starts in Aalesund, Norway, in 1955, where Polyform AS produced what it describes as "the world's very first inflatable, all-plastic buoy." Patent filed 1957, granted 1962. Polyform US spun off in 1978-79 as a separate Seattle-based operation, and the two companies now run independently with overlapping but distinct ranges.
Every A and F-series fender is rotationally moulded as a single-piece PVC body, with a high-pressure injection-moulded ribbed end cap and an inflation valve. No foam anywhere. The "foam fender" association comes from the dense, rigid feel of the PVC shell at 2 psi, which behaves quite differently to the softer textile inflatables charter captains now compare them against.
The flagship superyacht cylinder is the F-13: 29 × 76.5 in (74 × 194 cm), rated to absorb up to 3.8 tonne-metres of energy, sized for vessels up to 1,500 tonnes deadweight. Direct list USD $1,205. Lifetime warranty to the original purchaser, tested -30°C to +60°C. The F-series spans F-1 through F-13, with the F-11 (21 × 57.5 in) for yachts in the 18-25 m range.
Solid foam: the niche third category
True solid-foam fenders use a closed-cell EVA or polyurethane core, typically 50-100 kg/m³ density, wrapped in an abrasion-resistant skin that can be re-covered. Hauraki Fenders in New Zealand markets the Hurricane range as "the world's toughest unsinkable fenders," aimed at commercial dock work, lock walls, and exposed moorings. Xquip and the Fendequip dock and transom range cover similar use cases in Europe.
Two characteristics matter for superyacht use. They cannot deflate, so a puncture means a cosmetic skin repair, not a write-off. And the absorption physics differ: MIT's cellular-solids lecture notes describe how foam converts impact energy to heat through hysteretic flexure of the cell walls, absorbing roughly 40% more energy per cycle than an air-filled equivalent.
That advantage matters most for sustained dock rub through multiple tide cycles. For single high-energy impacts the air-filled fender's gradual deceleration feels less jarring. Most superyachts that carry solid-foam units use them in fixed positions: transom and swim platform where they stay rigged year-round, plus commercial-pier visits where lock-wall surge is expected.
Welded-seam textile inflatables
The modern superyacht primary fender. Heavy-duty coated textile welded into a low-pressure inflatable shell, typically operating at around 1 psi, with custom covers in charter-standard colours. SEARAFT and Fendequip dominate the European superyacht market; AERÉ Docking Solutions is the established American option; Ocean Magnus, Defenda, and Bridge Fenders fill out the rest of the price spectrum.
The biggest operational advantage is packability. Defenda's technical sheet confirms deflation to under 10% of inflated volume, a 90% storage reduction. A full eight-fender set folds into one or two duffel bags. Combined with weight savings, this is why they've become the default for active charter yachts.
Construction details, seam technology, and warranty terms are covered in the SEARAFT vs Fendequip pillar and the materials comparison. The key fact for this post: textile inflatables are structurally different from rotomoulded vinyl, despite both being labelled "inflatable."
Head-to-head: weight, storage, cost, lifespan
Side by side, the numbers are stark. Sportfish Outfitters benchmarks the killer datapoint: a Polyform A5 weighs 19 lb (8.6 kg) against an equivalent 28-inch welded-seam textile fender at 7 lb (3.2 kg), nearly three times heavier. Across an eight-fender deployment that's a 96 lb (44 kg) crew-handling delta every Med-mooring.
| Property | Air-inflated vinyl (Polyform F-series) | Solid foam (Hauraki, Xquip) | Welded-seam textile (SEARAFT, Fendequip) |
|---|---|---|---|
| Weight (28 in equivalent) | ~19 lb / 8.6 kg | ~25-35 lb / 11-16 kg | ~7 lb / 3.2 kg |
| Storage volume deflated | Inflated only (rigid) | Always full volume | <10% of inflated volume |
| Impact absorption profile | Non-linear air spring, peak at 50-70% deformation | Hysteretic (~40% more energy per cycle) | Intermediate, softens after wrinkling |
| Unsinkable | No (valve failure possible) | Yes | No (bladder failure possible) |
| Indicative list price | USD $1,205 (F-13, 74 cm) | EUR 800-1,500 (commercial dock unit) | USD $645 (Ocean Magnus 97 cm) |
| Warranty | Lifetime (Polyform US F-series) | 5-10 years skin, foam lifetime | 2-5 years standard |
| Typical service life | 8-25 years (covered storage) | 15+ years with re-covers | 5-10 years bladder material |
| Standard colours | White, blue, red, black | Black, navy, custom covers | Black, charcoal, navy plus custom covers |
Impact behaviour differs across the three. Air-filled rotomoulded fenders behave as a non-linear pneumatic spring: soft initial compression, gradual deceleration through about 50-70% deformation, then a sharp force spike. Foam dissipates energy hysteretically through cell-wall flexure, converting roughly 40% more energy per cycle into heat. Textile sits intermediate. On a 70-metre yacht alongside an exposed Adriatic quay with surge, foam keeps absorbing through each rub cycle while air just stores and returns it. For a single hard impact, the air-filled fender's gradual peak feels gentler on the hull.
The decision matrix: when each wins
The three categories don't compete head-on. Each has scenarios where it's the obvious answer.
Rotomoulded air-filled vinyl (Polyform-class) wins when:
- Sub-25 m yachts where weight differentials are smaller
- Permanent berth, single home port, no transit-storage problem
- Cost-conscious owner-run programmes
- Owners who value Polyform US's lifetime warranty as part of the long-term-cost calculation
Solid foam wins when:
- Permanent moorings, commercial piers, lock walls
- Sustained surge environments with multiple rub cycles per tide
- Transom and swim-platform protection where the fender stays rigged year-round
- Crews who don't want to manage inflation pressures or valve maintenance
Welded-seam textile inflatables win when:
- 30 m-plus superyachts on active Med or Caribbean rotation
- Below-decks or tender-garage storage is critical
- Custom sizes above 1.5 m diameter (Polyform tops out, Fendequip extends to 270 cm)
- Crew handleability matters. An 18 in textile fender packs into a duffel bag
- Charter visual standards require matched custom covers across the full inventory
For sizing across all three categories see our superyacht fender size guide.
The hybrid loadout: the honest captain's answer
Most experienced fleet captains don't pick one category. They carry all three. A typical 50-metre charter loadout looks like this:
- 6-8 primary welded-seam textile inflatables (SEARAFT or Fendequip 60 × 180 cm class) for daily Med berthing through the season
- 2-3 large Polyform F-11 or F-13 stowed below for emergency piling contact, lock walls, and lift-and-launch scenarios where you want a rigid, indestructible fallback
- 4-6 solid-foam transom and swim-platform fenders rigged permanently at the stern
Total cost is similar to an all-rotomoulded inventory at superyacht sizes once you factor in the F-13 price point, but operational flexibility is vastly better. Sportfish Outfitters quotes captain wisdom directly: "keep one or two molded fenders for emergencies while using lightweight inflatables for everyday travel." That's the honest answer no single brand will give you.
How Mercer Yachting spec's the loadout
We don't sell against any single category. We start with yacht length, displacement, home port, berthing pattern, and the captain's existing fender experience, and we build a three-category loadout from first principles. Most clients end up with welded-seam textile as the primary set, two Polyform F-class as emergency backups, and dedicated solid-foam transom protection.
We purchase SEARAFT direct from the Nijmegen factory and Fendequip direct from the South West UK. Polyform F-series and solid-foam units come through our Malta and Mediterranean supplier network. Transparent pricing, four-business-hour quote turnaround, Mediterranean delivery within 4-7 days of dispatch.
Tell us the yacht and the berthing pattern. We'll come back with two configurations at different price points.
Frequently asked questions
Are Polyform fenders foam-filled or air-filled?
Air-inflated, not foam-filled. Polyform A and F-series fenders use a rotomoulded PVC shell with a valve and around 2 psi internal pressure. The "foam fender" label is a category mix-up.
What's the lightest type of superyacht fender?
Welded-seam textile, by a wide margin. Sportfish Outfitters benchmarks a 28 inch welded-seam fender at 7 lb (3.2 kg) against a Polyform A5 at 19 lb (8.6 kg), nearly three times heavier.
Which fender type lasts longest?
Polyform US F-series carries a lifetime warranty; forum reports show 8-25 years with covered storage. Solid foam outlasts both because the core stays good even when the skin abrades. Textile inflatables run 5-10 years.
Why do superyacht captains use multiple fender types?
No single construction wins every scenario. A typical fleet loadout: 6-8 textile inflatables for daily berthing, 2-3 large Polyform F-class for emergency piling work, and 4-6 solid-foam fenders rigged permanently at the transom.
What's the right choice for a 30m charter yacht?
Welded-seam textile inflatables as the primary set, plus two large Polyform spheres as backups. Below-decks storage and crew handleability matter on an active Med season.
Are solid-foam fenders unsinkable?
Yes. Closed-cell EVA or polyurethane cores have no air cavity to lose, so they cannot deflate or sink. Hauraki Hurricane and Xquip market this as their primary value proposition.
How does Polyform F-13 compare to textile inflatables on cost?
Polyform US F-13 lists at USD $1,205 direct. Ocean Magnus 97 × 210 cm lists at USD $645 on Tradeinn. Sizes aren't identical, but textile inflatables are generally cheaper per unit at superyacht scale; the F-13's lifetime warranty shifts the lifetime-cost picture.
Which is better for tender garage protection?
Welded-seam textile wins, because Defenda's data shows deflation to under 10% of inflated volume. For permanent transom and swim-platform protection, solid foam is the better fit.
Sources: Polyform AS company history; Polyform US F-13 product datasheet; Polyform US F-series corporate page; Sportfish Outfitters: molded vs welded-seam fender weight benchmark; Defenda technical: 90% deflation volume reduction; Hauraki Hurricane fender range; MIT 3.054 Cellular Solids: foam energy absorption physics. Mercer Yachting purchases across all three fender categories and has no exclusive arrangement with any single brand. See also: Superyacht Fenders hub.