History 43 Navigation 15 Sea-power 10 Naval art and science 8 Warships 8 Navies 7 Biography 6 more ... Handbooks, manuals, etc 6 History, Naval 6 Ships 6 Merchant marine 5 Military policy 5 Boats and boating 4 Naval strategy 4 Shipbuilding 4 Submarines (Ships) 4 Aircraft carriers 3 Aviation 3 Battleships 3 Congresses 3 Dictionaries 3 Leadership 3 Lists of vessels 3 Nautical astronomy 3 Naval architecture 3 Pictorial works 3 Seamanship 3 Weapons systems 3 Admirals 2 Aeronautics, Military 2 less ...