I have had the awesome oppurtunity to experience both Marine and Navy OCS. Im currently in my 11th week of 12 at Navy OCS. I went through four of ten weeks at Marine OCS in the summer of 2006 before busting my foot and getting sent home. Whoever said that Marine OCS is tougher but Navy OCS sucks more was right on. Marine PT was ten times harder but the mind game of Navy OCS makes it difficult in its own way. But thats all im gonna say about both of them b/c they both are difficult in their own ways.