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. This vinyl acts as a cover, but moisture (and humidity) can still seep through seams and stitching, leading to mold, mildew, and vinyl-pinking.

For this reason, the best choice is a high-density polyurethane foam specifically designed to address these problems: CushionRite® Antimicrobial Cushion Foam.

Here’s why it’s the ideal choice:

• Antimicrobial & Antipinking: It's treated to inhibit mold and mildew growth and to prevent the common "pinking" stains that can ruin marine vinyl.
• High-Density (1.8 lbs./cu. ft.): It meets the high-density standard, offering durability and support for 3-5 years.
• Firmness Options: It's available in Medium, Firm, and Extra Firm to get the feel you want.

Pro Tip: Always pair this foam with a waterproof, marine-grade vinyl cover to keep it as dry as possible and extend its life.

Shop CushionRite Antimicrobial Foam

Best Foam for Sailboat Cockpit Cushions

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

Why Closed Cell Foam Works Best:

• Water-Repellent and Buoyant: It 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): It's built to withstand daily use, heavy foot traffic, and years of exposure to the elements.
• Firm Support: It's extremely firm, 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.

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 essential terms to know when researching foam in our “Choosing the Best Foam for Cushions — 5 Key Terms to Know” article.