Extended Operational and Trade Vocabulary
Pre-1900 Maritime History glossary
The pre-twentieth-century maritime vocabulary: historic vessel types (the Dutch aak, the Acapulco galleon), navigation statutes (the Act of Navigation 1651), naval administration bodies, and the sailing-era trades and institutions. Grounds each term in the historic ship, voyage, or statute it names, the deep-history counterpart to the modern history section.
438 defined terms.
Showing 250 on this page (page 1 of 2).
A
- Aak
- A flat-bottomed Dutch inland barge of the seventeenth and eighteenth centuries used on the Rhine and Maas for cargo transport.
- Able Seaman
- STCW-rated deck rating qualified beyond ordinary seaman.
- Acapulco Galleon
- Spanish trading vessel that crossed the Pacific between Manila and Acapulco from 1565 to 1815 carrying silver and silks.
- Admiralty Board
- The British naval administration body that managed warship construction, manning, and operations from the seventeenth century.
- Admiralty Chart
- Nautical chart issued by the UK Hydrographic Office.
- Aegir
- In Old Norse seafaring tradition, the giant personifying the sea, invoked by Viking mariners.
- Aft Cabin
- The stern compartment in a sailing ship typically reserved for the captain or senior officers.
- Akers Mekaniske Verksted
- Norwegian shipyard founded in Christiania in 1841, building early Scandinavian steamships.
- Allan Line
- Canadian shipping company founded by Hugh Allan in 1854 carrying mail and emigrants between Liverpool and Quebec.
- Almirante
- Spanish naval rank equivalent to admiral, used in the Carrera de Indias treasure-fleet system.
- Amerigo Vespucci
- Florentine navigator whose voyages between 1499 and 1502 led to the naming of the Americas.
- Anchor watch
- Watch maintained on anchored vessel.
- Ann McKim
- American merchant ship launched at Baltimore in 1833, regarded as a precursor of the clipper type.
- Aphract
- An ancient Greek warship lacking a full deck over the rowers, distinguished from the cataphract.
- Apprentice
- Cadet or trainee enrolled in an approved program leading to a Certificate of Competency.
- Arsenal of Venice
- The state shipyard of the Venetian Republic founded in 1104, employing thousands at its medieval peak.
- Articles of War
- The disciplinary code governing the Royal Navy, first codified in 1652 and revised in 1749.
- Astrolabe
- Medieval Arab and European altitude-measuring instrument adapted as the mariner's astrolabe in the fifteenth century.
- Atlantic Packet Trade
- Scheduled sailing-packet service between New York and Liverpool inaugurated by the Black Ball Line in 1818.
- Avast
- A traditional shipboard command meaning to cease or stop an action, of uncertain Dutch or Italian origin.
B
- Backstaff
- A navigational instrument invented by John Davis in 1594 for measuring solar altitude without looking at the sun.
- Baltimore Clipper
- A fast topsail schooner developed on Chesapeake Bay in the late eighteenth century, used as privateer and slaver.
- Bantry Bay
- Irish anchorage and site of the 1689 and 1796 French naval expeditions.
- Barge
- Tank vessel used for bunker delivery alongside ocean-going ships in port and at anchorage.
- Barque
- A sailing vessel of three or more masts, square-rigged on all but the aftermost, which carries fore-and-aft sails.
- Barquentine
- A sailing vessel square-rigged on the foremast only, with fore-and-aft sails on the remaining masts.
- Batavia
- Dutch East India Company headquarters in Java founded in 1619 and a key port of the spice trade.
- Battle of Lepanto
- 1571 galley battle in which the Holy League defeated the Ottoman fleet in the Gulf of Patras.
- Battle of Sluys
- English naval victory of June 24, 1340 opening the Hundred Years War at sea.
- Battle of the Saintes
- April 12, 1782 engagement in the West Indies where Rodney defeated the French fleet under de Grasse.
- Battle of Trafalgar
- Royal Navy victory of 21 October 1805 under Nelson over the combined Franco-Spanish fleet.
- Beak
- The projecting structure at the bow of a galley used for ramming or boarding.
- Beam Ends
- A ship is said to be on her beam ends when heeled so far that the deck approaches vertical.
- Belaying pin
- Removable wooden or metal pin in a rail for belaying running rigging.
- Belfast
- Irish shipbuilding port; Harland and Wolff was founded there in 1861.
- Bellerophon, HMS
- Third-rate ship of the line launched in 1786 aboard which Napoleon surrendered on July 15, 1815.
- Berthon Boat
- Collapsible lifeboat patented by Edward Lyon Berthon in 1851.
- Bilander
- A small two-masted European merchant vessel of the seventeenth and eighteenth centuries with a lateen mainsail.
- Bireme
- Ancient Mediterranean galley with two banks of oars.
- Birkenhead
- English shipbuilding town on the Mersey where Cammell Laird built iron vessels from the 1820s.
- Black Ball Line
- New York shipping firm that began the first scheduled transatlantic packet service in January 1818.
- Blackwall Frigate
- A class of three-masted full-rigged ships built at Blackwall Yard for the India trade from the 1830s.
- Block
- Pulley used with rope to make a tackle.
- Bluenose
- Canadian fishing and racing schooner launched at Lunenburg in 1921 (terminus of the working-schooner tradition).
- Boatswain
- Senior unlicensed deck rating; bosun.
- Bomb Vessel
- A small naval ship mounting one or two heavy mortars for shore bombardment, developed by the French in the 1680s.
- Boston Tea Party
- Colonial protest of December 16, 1773 in which East India Company tea was dumped from three ships into Boston Harbor.
- Bounty, HMS
- Royal Navy armed transport whose crew mutinied under Fletcher Christian on April 28, 1789.
- Bowditch, Nathaniel
- American mathematician whose New American Practical Navigator, first published in 1802, became standard for merchant officers.
- Bowsprit
- Spar extending forward from the stem for headsails.
- Breechloader
- Naval gun design loaded from the rear, adopted in the Royal Navy after the 1859 Armstrong gun trials.
- Brest
- French Atlantic naval port and arsenal developed under Richelieu and Colbert in the seventeenth century.
- Brig
- A two-masted vessel square-rigged on both masts.
- Brigantine
- Two-masted vessel with square-rigged foremast and fore-and-aft mainmast, common in eighteenth and nineteenth century coastal trade.
- Bristol
- English Atlantic port from which John Cabot sailed in 1497 and a center of the slave and West India trades.
- Britannia, RMS
- Cunard Line paddle steamer of 1840, the company's first transatlantic mail vessel.
- Buccaneer
- A privateer of the seventeenth-century Caribbean operating from Tortuga and Port Royal.
- Bucentaur
- The state galley of the Doge of Venice used in the annual Marriage of the Sea ceremony.
- Buss
- Dutch herring-fishing vessel of the sixteenth and seventeenth centuries.
C
- Cabotage
- National reservation of coastwise trade to vessels of the flag State.
- Caique
- A light wooden vessel of the eastern Mediterranean used for trade and fishing.
- Cammell Laird
- Birkenhead shipbuilder formed in 1903 from the union of Cammell of Sheffield and Laird Brothers, the latter founded 1828.
- Cape Horn
- Southern tip of South America, first rounded by Schouten and Le Maire in January 1616 and named for the Dutch town of Hoorn.
- Cape of Good Hope
- Southern African headland rounded by Bartolomeu Dias in 1488, opening the sea route to India.
- Caravel
- Small lateen-rigged Iberian exploring vessel of the fifteenth century, used by Portuguese explorers along Africa.
- Cargo Manifest
- Statutory list of cargo carried.
- Carrack
- Three or four masted ocean-going merchantman developed in fifteenth century Iberia; example, Santa Maria.
- Carronade
- A short, large-caliber naval gun developed by the Carron Company of Falkirk in 1778.
- Cartagena de Indias
- Spanish colonial port on the Caribbean coast of present-day Colombia, fortified as a treasure-fleet rendezvous.
- Catamaran
- Twin-hull vessel with high transverse stability.
- Cathead
- Projecting beam at the bow used to hold the anchor clear of the hull when weighed (historical).
- Chain Pump
- A continuous-chain bilge pump used aboard large sailing warships from the late seventeenth century.
- Charles W. Morgan
- American whaling bark launched at New Bedford in 1841, preserved at Mystic Seaport.
- Chatham Dockyard
- English royal dockyard on the Medway active from 1567 to 1984, birthplace of HMS Victory.
- Chebec
- A three-masted Mediterranean vessel combining lateen and square sails, favored by Barbary corsairs.
- China Tea Trade
- The export of tea from Canton to Britain that, from 1834 onward, drove demand for fast clipper ships.
- Chip Log
- A speed-measuring device using a knotted line and triangular wooden float streamed astern.
- Chronometer
- Precision timekeeper carrying UT1/UTC for celestial navigation.
- Clermont
- Robert Fulton's steamboat that began commercial Hudson River service in August 1807.
- Clipper
- Mid-nineteenth century sharp-hulled fast sailing ship built for tea, opium, wool, and California trades.
- Coal Trade
- The east coast English collier traffic from the Tyne and Wear that trained generations of British seamen.
- Coelho, Gonçalo
- Portuguese navigator who commanded the 1501 to 1502 voyage along the Brazilian coast that carried Vespucci.
- Cog
- Single-masted Hanseatic League cargo carrier of the high medieval Baltic and North Sea.
- Columbiad
- Heavy American naval and coastal gun introduced in 1811.
- Columbus, Christopher
- Genoese navigator whose 1492 voyage in Niña, Pinta, and Santa María opened sustained European contact with the Americas.
- Comet
- Henry Bell's paddle steamer of 1812, the first commercial passenger steamer in European waters, operating on the Clyde.
- Compass Rose
- Wind rose device printed on charts since the portolan era of the late thirteenth century.
- Constitution, USS
- American 44-gun frigate launched in 1797 and victor over HMS Guerriere in 1812.
- Convoy System
- Organized escort of merchant ships used by the Royal Navy during the Napoleonic Wars and again after 1917.
- Cook, James
- British naval officer and surveyor whose three Pacific voyages between 1768 and 1779 mapped vast areas of ocean.
- Coracle
- A small round basket boat of British and Welsh inland tradition, recorded since classical antiquity.
- Corvette
- Light surface combatant smaller than a frigate.
- Cromster
- A small armed merchant or naval vessel of the late sixteenth century, often rigged as a galleass.
- Crow's Nest
- An elevated lookout fitted at the masthead, attributed to the Arctic whaling captain William Scoresby Senior around 1807.
- Cumberland Fleet
- Early Thames yacht club founded in 1775, ancestor of the Royal Thames Yacht Club.
- Cunard, Samuel
- Nova Scotia merchant who founded the British and North American Royal Mail Steam Packet Company in 1840.
- Cutter
- A single-masted vessel with a deep hull and large sail area, used as a revenue and naval auxiliary craft.
- Cutty Sark
- Preserved tea clipper at Greenwich, built 1869.
D
- Dalriada
- Early medieval Gaelic seafaring kingdom spanning western Scotland and northeastern Ireland.
- Dampier, William
- English navigator and buccaneer whose voyages from 1679 to 1711 produced influential charts of the Pacific.
- Davit
- Curved crane for hoisting and lowering boats and stores.
- Davy Jones's Locker
- Sailor folklore name for the seabed and resting place of drowned mariners.
- Dead reckoning
- Position calculation from course, speed and time without external fixes.
- Deadweight tonnage
- DWT, total weight a vessel can carry.
- Defoe, Daniel
- English author whose 1719 novel Robinson Crusoe drew on the marooning of Alexander Selkirk.
- Demi-Culverin
- A medium long-range naval gun of the sixteenth and seventeenth centuries.
- Deptford
- Royal dockyard on the Thames founded by Henry VIII in 1513 and closed in 1869.
- Devonport
- English royal dockyard at Plymouth established in 1691 as Plymouth Dock.
- Dhow
- Lateen-rigged Arab and East African trading vessel of the western Indian Ocean.
- Discovery, HMS
- Royal Navy barque-rigged exploration vessel of 1789 that accompanied Vancouver to the Pacific Northwest.
- Dogger
- Two-masted English North Sea fishing vessel of the seventeenth century.
- Dogger Bank
- North Sea fishing ground and the site of the 1781 Anglo-Dutch naval engagement.
- Doldrums
- Equatorial region of light and variable winds within the ITCZ.
- Don John of Austria
- Commander of the Holy League fleet that defeated the Ottomans at Lepanto in 1571.
- Dover Patrol
- Royal Navy command guarding the Dover Strait, formally constituted in 1914 but with antecedents in earlier Channel guard.
- Dreadnought, HMS (1875)
- Royal Navy turret battleship launched in 1875 (predecessor of the better-known 1906 ship).
- Drebbel, Cornelis
- Dutch inventor who in the 1620s tested an early oar-propelled submersible in the Thames.
- Dromon
- Byzantine war galley of the sixth to twelfth centuries armed with Greek fire.
- Dry dock
- Basin pumped dry for hull work.
- Dundee
- Scottish East Coast port and a major center of nineteenth-century whaling and jute-clipper construction.
- Dungeness
- English headland on the Channel, a long-established pilotage and lookout station.
- Dutch East India Company (VOC)
- Chartered 1602, the first multinational joint-stock company and dominant Asian trader of the seventeenth century.
- Dutch West India Company (WIC)
- Trading company chartered in 1621 to operate in the Atlantic and the Americas.
E
- East India Company (English)
- Joint-stock trading company chartered by Elizabeth I on December 31, 1600.
- East Indiaman
- Large merchant vessel of the various East India Companies.
- Eddystone Lighthouse
- Lighthouse on the Eddystone Rocks off Plymouth, first built by Henry Winstanley in 1698 and rebuilt by Smeaton in 1759.
- Elder, John
- Clyde marine engineer whose compound steam engine, patented in 1853, transformed ocean steamship economics.
- Endeavour, HMS
- Royal Navy bark in which Cook made his first Pacific voyage from 1768 to 1771.
- Erebus, HMS
- Franklin Expedition wreck located in 2014 in Wilmot and Crampton Bay.
- Ericsson, John
- Swedish-American engineer who designed the screw propeller used in USS Princeton (1843) and the ironclad USS Monitor.
- Essex, Whaleship
- Nantucket whaler stove by a sperm whale on November 20, 1820, the inspiration for Melville's Moby-Dick.
- Exeter Canal
- English ship canal opened in 1566, the first in the country to use pound locks.
F
- Falmouth Packet
- Royal Mail packet brigs and brigantines operating from Falmouth between 1689 and 1851.
- Fenian Ram
- Early submarine designed by John Philip Holland and launched in 1881.
- Figurehead
- Ornamental carving on the bow of a sailing vessel, often preserved by museums.
- First Rate
- Royal Navy ship of the line with 100 or more guns.
- Fitch, John
- American inventor who operated an experimental steamboat on the Delaware River in 1787.
- Fluyt
- Dutch cargo carrier of the late sixteenth and seventeenth centuries, optimized for low crew costs.
- Fly-Boat
- An anglicization of the Dutch fluyt used in seventeenth-century English merchant service.
- Forecastle
- Forward part of the upper deck; forward crew accommodation.
- Forfarshire, SS
- Paddle steamer wrecked off the Farne Islands on September 7, 1838, the rescue led by Grace Darling.
- Fram
- Polar exploration ship of Nansen and later Amundsen, launched 1892.
- Franklin Expedition
- 1845 Royal Navy Arctic expedition lost in search of the Northwest Passage.
- Frigate
- Naval combatant smaller than destroyer.
- Frobisher, Martin
- English privateer and explorer who made three voyages between 1576 and 1578 seeking the Northwest Passage.
- Fulton, Robert
- American engineer whose North River Steamboat of 1807 inaugurated commercial steam navigation in the United States.
G
- Galleas
- A large oared and sailing warship of the sixteenth century combining galley and galleon features.
- Galleon
- Iberian sailing warship and treasure carrier of the sixteenth and seventeenth centuries.
- Galley
- Oared Mediterranean warship type from antiquity into the seventeenth century.
- Gama, Vasco da
- Portuguese navigator whose voyage of 1497 to 1499 opened the direct sea route from Europe to India.
- George III, HMS Royal
- First-rate Royal Navy ship of the line launched at Chatham in 1788.
- Gerald of Wales
- Twelfth-century churchman whose accounts describe early Welsh and Irish coastal craft.
- Glasgow
- Scottish city on the Clyde; the Clyde shipbuilding district produced about a fifth of world merchant tonnage by 1913.
- Golden Hind
- Sir Francis Drake's flagship in the circumnavigation of 1577 to 1580, originally named Pelican.
- Goree
- Island off Senegal used as a transatlantic slave-trading entrepot from the seventeenth century.
- Grand Banks
- Atlantic fishing grounds off Newfoundland, central to cod history.
- Grand Turk
- Salem privateer and East India trader built in 1781, illustrative of early American maritime commerce.
- Great Britain, SS
- Brunel's iron-hulled screw steamer launched at Bristol in 1843, the first ocean-going ship of her type.
- Great Eastern, SS
- Brunel and Scott Russell's iron steamship of 1858, the largest vessel built in the nineteenth century.
- Great Harry
- Henry Grace à Dieu, English carrack launched in 1514 and the largest warship of her day.
- Great Western, SS
- Brunel's wooden paddle steamer of 1837 that crossed from Bristol to New York in April 1838.
- Greenock
- Scottish Clyde port and shipbuilding town active from the late seventeenth century.
- Greenwich Hospital
- Royal naval hospital founded in 1694 for seamen of the Royal Navy.
- Greenwich Mean Time
- Time standard at the prime meridian, formerly used for tidal predictions.
- Gross Register Tonnage
- A volumetric measure of a merchant ship's enclosed space, codified by the Moorsom system in the UK Merchant Shipping Act of 1854.
- Guildhall of the Hanse
- Steelyard on the Thames in London serving as the Hanseatic kontor until 1598.
- Gunwale
- Upper edge of the hull at the side.
H
- Half Moon
- The Dutch East India Company yacht in which Henry Hudson explored the river that bears his name in September 1609.
- Hanseatic League
- Medieval North European trading confederation centered on Lubeck.
- Harland and Wolff
- Belfast shipbuilder founded in 1861 by Edward Harland and Gustav Wolff.
- Harrison, John
- English clockmaker whose marine chronometers H1 (1735), H2 (1741), H3 (1759), and H4 (1759) solved the longitude problem.
- Hawser
- Heavy rope or cable for mooring or towing.
- Hayes, Bully (William Henry)
- Notorious nineteenth-century South Pacific blackbirder.
- Hecla, HMS
- Royal Navy bomb vessel that carried Parry on Arctic voyages from 1819 onward.
- Helm
- Steering control of a vessel; the wheel and rudder.
- Hennebique
- Reinforced concrete system used in early twentieth-century ship construction, of late nineteenth-century origin.
- Hibernia, RMS
- Cunard paddle steamer of 1843 serving the Liverpool to Boston route.
- Holland, John Philip
- Irish-American engineer whose Holland VI of 1897 became the first submarine commissioned by the United States Navy.
- Holyhead Packet
- Mail service between Holyhead in Anglesey and Dublin, operating from the seventeenth century.
- Hong Merchants
- Cantonese guild that monopolized European trade at Canton under the Qing system until 1842.
- Hooghly River
- Distributary of the Ganges and the maritime approach to Calcutta, surveyed by the East India Company from the seventeenth century.
- Hoy
- Small English coasting vessel of the seventeenth and eighteenth centuries.
- Hudson, Henry
- English navigator who explored the Hudson Bay and Hudson River in 1610 and 1609 respectively.
- Hudson's Bay Company
- English trading company chartered by Charles II on May 2, 1670, the oldest continuously operated commercial corporation in North America.
- Hulc
- A medieval cargo vessel of northern Europe distinguished from the cog by its rounded hull form.
- Hull, Kingston upon
- English east coast port and base of the Wilson Line and the Greenland whaling fleet.
I
- Imperieuse, HMS
- Royal Navy frigate famous under Lord Cochrane during the Napoleonic Wars.
- Implacable, HMS
- French-built third-rate ship of the line captured at Trafalgar and used by the Royal Navy until 1949.
- Inchcape Rock
- Sandstone reef off the Angus coast on which the Bell Rock Lighthouse was built by Robert Stevenson between 1807 and 1810.
- Indefatigable, HMS
- Razee frigate famous under Sir Edward Pellew in the 1790s.
- Inman Line
- Liverpool-based steamship company founded by William Inman in 1850 as a rival to Cunard.
- Investigator, HMS
- Royal Navy sloop in which Matthew Flinders circumnavigated and charted Australia from 1801 to 1803.
- Iron Steamboat
- A vessel with hull of wrought iron rather than wood, pioneered by Aaron Manby and launched on the Thames in 1822.
- Isle of Man Steam Packet Company
- Founded in 1830 and the longest continuously operating passenger steamship company in the world.
J
- Jack Tar
- Colloquial term for a British seaman, recorded from the early eighteenth century.
- Jangada
- A Brazilian sailing raft of pre-Columbian origin still used by inshore fishermen.
- Jeannette, USS
- Polar exploration vessel crushed in Arctic ice in June 1881 during the De Long expedition.
- John Wood
- Port Glasgow shipbuilder who built Henry Bell's Comet in 1812.
- Jolly boat
- Light general-purpose ship's boat.
- Junk
- Chinese flat-bottomed seagoing vessel with battened lugsails, attested from the Han dynasty.
K
- Karlskrona
- Swedish royal naval base founded in 1680 on the Baltic and a UNESCO World Heritage Site.
- Keel
- Principal longitudinal member at the bottom of the hull.
- Keelhauling
- A naval punishment, particularly in the Dutch navy, abolished in the seventeenth and eighteenth centuries.
- Ketch
- Two-masted rig with mizzen forward of the rudder post and shorter than the main.
- King's Lynn
- Norfolk port and former Hanseatic warehouse town, the only surviving English Hanseatic warehouse standing there.
- Knot
- One nautical mile per hour.
- Kobenhavn
- Capital of Denmark and seat of the Danish Asiatic Company chartered in 1732.
L
- L'Orient
- French flagship destroyed at the Battle of the Nile, 1798.
- Laird Brothers
- Birkenhead shipbuilder founded by William Laird in 1828, predecessor of Cammell Laird.
- Lateen Sail
- A triangular sail set on a long yard angled across the mast, characteristic of Mediterranean rigs.
- Lavery, Brian
- Modern maritime historian, included here only as scholarly reference is not the entry's purpose; omit.
- Leeward
- Downwind.
- Lepanto
- See Battle of Lepanto, 1571.
- Lightship
- Vessel mass excluding cargo, fuels, water, stores, and persons.
- Lind, James
- Royal Navy surgeon whose 1747 controlled trial demonstrated citrus as a cure for scurvy.
- Liner
- Vessel operating to a published schedule on a fixed route.
- Liverpool
- English port that grew rapidly with the West India and African trades from the eighteenth century.
- Lloyd, Edward
- London coffee-house proprietor whose establishment, mentioned in print in 1688, became the nucleus of Lloyd's of London.
- Lloyd's Register
- LR, UK-headquartered classification society and IACS member founded 1760.
- Log
- Instrument measuring speed and distance run; daily journal.
- London Missionary Society Ship
- The vessel Duff sailed from London in 1796 carrying the first Protestant missionaries to the South Pacific.
- Longitude Act 1714
- British statute offering a prize of up to £20,000 for a practical method of determining longitude at sea.
- Lord High Admiral
- Senior English naval office held by various royal personages and statesmen from the fourteenth century.
- Lubeck
- North German Hanseatic port, the league's effective capital from the thirteenth to the sixteenth century.
- Lugger
- A small fore-and-aft rigged vessel using lug sails, common in Channel coastal trade and smuggling.
M
- Maersk, Arnold Peter Moller
- Danish shipowner whose Svendborg firm of 1904 grew into the modern Maersk group (founder lived 1876 to 1965).
- Magellan, Ferdinand
- Portuguese navigator in Spanish service whose 1519 expedition completed the first circumnavigation of the globe in September 1522.
- Mainsail
- Principal sail set on the mainmast.
- Manila Galleon
- The Spanish trans-Pacific trade route between Manila and Acapulco, operated from 1565 to 1815.
- Marblehead
- Massachusetts fishing and privateering port, source of many Continental Navy seamen.
- Marc Brunel
- French-born British engineer who designed block-making machinery installed at Portsmouth Dockyard from 1803.
- Marquesas Islands
- Pacific archipelago visited by Mendaña in 1595 and central to South Sea whaling lore.
- Mary Rose
- Tudor warship sunk in 1545 in the Solent and raised in 1982.
- Mast step
- Block in which the heel of a mast rests.
- Master and Commander
- A Royal Navy rank between lieutenant and post-captain, formalized in 1718.
- Maury, Matthew Fontaine
- United States Navy officer whose 1855 Physical Geography of the Sea established modern oceanography.
- Mayflower
- 1620 English vessel that carried the Pilgrim Fathers to Plymouth.
- Mediterranean Pass
- A document issued by the Royal Navy from 1662 to protect British merchant ships from Barbary corsairs.
- Merchant Adventurers
- Sixteenth-century English trading company specializing in cloth exports to the Low Countries.
- Merchant Shipping Act 1854
- British statute codifying the regulation of merchant shipping under the Board of Trade.
- Merchant Shipping Act 1876
- British statute that introduced the load line championed by Samuel Plimsoll.
- Merchant Shipping Act 1894
- Consolidating British statute that remained the principal merchant shipping law for most of the twentieth century.
- Mizzen
- Aftermost mast in a yawl or ketch; sail set on it.
- Monitor, USS
- Ericsson-designed ironclad turret ship launched January 30, 1862 and engaged at Hampton Roads on March 9, 1862.
- Mooring buoy
- Buoy to which a ship may secure.
- Morgan, Henry
- Welsh privateer who sacked Panama in January 1671 and later served as Lieutenant Governor of Jamaica.