As another top-level comment mentioned, depending on the sheer strength, it could be used in composite structures.<p>Take a 2&#x27;x2&#x27; 1&quot; thick piece of foam. Laminate some fiberglass onto both sides of it. This is basically how modern boat hulls are constructed. Extremely light, rigid, insulated and durable.<p>WAG, but if it would allow you to replace 1 ton of foam on a 40&#x27; yacht, that&#x27;s one ton of extra cargo&#x2F;amenities you could carry instead and maintain the same water line. Or alternatively you could produce a faster boat with less wetted area.<p>I&#x27;m sure a real engineer has a better idea of practical applications. But I like cruising yachts so. :-)