http://www.restorides.com/~dub/ThjisHull/ThjisHull001.htm Above is the link to the FEA report for Thjis' hull concept. At 200 psi it had a 3.75X safety factor, which isn't made clear in the report. You can see the even pressure distribution, however. Warren. __________________________________ Do you Yahoo!? The New Yahoo! Search - Faster. Easier. Bingo. http://search.yahoo.com