 The shipwrecked dhow was approximately 21 feet ( 6 @.@ 4 m ) wide and 58 feet ( 18 m ) long and is remarkable for two reasons ; it is the first ancient Arabian ship to be found and excavated , and its planks were sewn together using a thin rope made of coconut fibres rather than using the more traditional methods of pegs or nails used in Arabia in later centuries . 
