Q: How strong will my fast trawler be? A: In a word, VERY! O.K. we all think we want our yacht strong, but strong is really "qualitative" and not specific enough to meet our needs in engineering the best boat for all conditions one might encounter. We want to deal with the structural issues in more "quantitative" ways. What does an expedition yacht need to be, to be successful? One of the most important qualities is "stiff". We need it to resist the forces on the structure that are imposed on it by using it in the sea. In its general application, cored composite or sandwich type construction is specifically developed to deliver structure that is extremely "stiff". It does this by acting as a virtual "I" beam element where high tech fiberglass skin laminates are held in tension by a core materials that is in essence the "web" of the "I" beam. This creates power catamaran hulls and structures that are many times stiffer and lighter than single skinned materials be it metal, wood or glass. See diagram.