Foam Series: Choosing the Best Foam for Marine Exterior Cushions

In this guide, we’ll compare top foam options for marine exterior seating, based on whether you're working on sailboat cockpit cushions or upholstered seats for a powerboat or pontoon.

Best Foam for Powerboat & Pontoon Seats

Powerboat and pontoon seats are typically upholstered in waterproof vinyl. That makes polyurethane foam — which naturally absorbs water — a suitable option only when used with a waterproof cover like marine-grade vinyl.

Medium-Density vs. High-Density Polyurethane Foam:

Medium Density:

• Commonly used by OEM boat builders.
• More affordable — approx. 35–40% cheaper than high density.
• Ideal for weekend or occasional boaters.
• Sailrite’s option: CushionRite® Standard Antimicrobial Foam
  • Available in soft, medium and firm firmness levels
  • Multiple thicknesses and sizes

Shop CushionRite Standard Antimicrobial Foam

High Density:

• Longer lifespan and greater durability.
• Perfect for frequent use or long-term installations.
• Sailrite’s option: CushionRite® Premium Antimicrobial Foam (Firm)
  • 2.8 lbs. per cubic foot.
  • Lasts up to 12 years.

Shop CushionRite Premium Antimicrobial Foam (Firm)

Pro Tip: Always pair polyurethane foam with a waterproof vinyl cover to keep the foam dry and extend its life.

Best Foam for Sailboat Cockpit Cushions

Sailboat cockpit cushions are exposed to more moisture — and sometimes end up overboard. That’s why we recommend closed cell CushionRite® Flotation Antimicrobial Foam for this application.

Why Closed Cell Foam Works Best:

• Water-repellent and buoyant: Won’t absorb water and can float — ideal for cushions that might get wet or tossed into the water.
• High density (3–4.5 lbs./ft³): Built to withstand daily use, heavy foot traffic and years of exposure to the elements.
• Firm support: Perfect for cockpit areas where cushions are frequently stepped on.
• Versatile: Can be covered in any marine-grade fabric.

Shop CushionRite Flotation Antimicrobial Foam

This foam is also a popular choice for bosun’s chairs thanks to its firm structure and water-resistant properties.

Final Thoughts

There's no one-size-fits-all solution for marine exterior foam. The best foam depends on how often your boat is used, what type of seating you're upholstering and how much exposure to water the cushions will face.

Shop All Marine Exterior Foam

To learn more details about each type of foam mentioned here (and more!) check out our “Comparing Types of Upholstery Foam” blog. You can also read more about important terms to know when researching foam in our “Choosing the Best Foam for Cushions — 5 Key Terms to Know” article.