The invasion of sipan also required a much longer sea lift than at normandy. By design, the men who invaded sipan would be stranded there for three months before significant reinforcements or supplies could reach them. In his book, eagle against the sun, ronald h specter describes how the marianus are going to be a different animal than terrawa n the coral s was. They combined all the hazards which american soldiers and marines had learned to dread in their earlier island campaigns,. A fringing coral reef protecting a shallow lagoon, rugged jungle terrain and lots of limestone and coral caves for bunkers and artillery positions.