Of the vast majority of the crewmen, soldiers, sailors and gunners alike, nothing has been recorded. The only source of information for these men has been through osteological analysis of the human bones found at the wrecksite. An approximate composition of some of the crew has been conjectured based on contemporary records. The "Mary Rose" would have carried a captain, a master responsible for navigation, and deck crew. There would also have been a purser responsible for handling payments, a boatswain, the captain's second in command, at least one carpenter, a pilot in charge of navigation, and a cook, all of whom had one or more assistants (mates). The ship was also staffed by a barber-surgeon who tended to the sick and wounded, along with an apprentice or mate and possibly also a junior surgeon. The only positively identified person who went down with the ship was Vice-Admiral George Carew. McKee, Stirland and several other authors have also named Roger Grenville, father of Richard Grenville of the Elizabethan-era "Revenge", captain during the final battle, although the accuracy of the sourcing for this has been disputed by maritime archaeologist Peter Marsden.