     a ferry (or ferryboat) is a boat or ship (a merchant vessel) used to carry (or ferry) primarily passengers, and sometimes vehicles and cargo as well, across a body of water. most ferries operate on regular, frequent, return services. a passenger ferry with many stops, such as in venice, italy, is sometimes called a water bus or water taxi.  thumb|passenger area of a norwegian ferry ferries form a part of the public transport systems of many waterside cities and islands, allowing direct transit between points at a capital cost much lower than bridges or tunnels. however, ship connections of much larger distances (such as over long distances in water bodies like the mediterranean sea) may also be called ferry services, especially if they carry vehicles. ==history==  ===in ancient times=== the profession of the ferryman is embodied in greek mythology in charon, the boatman who transported souls across the river styx to the underworld. speculation that a pair of oxen propelled a ship having a water wheel can be found in 4th century roman literature "anonymus de rebus bellicis". though impractical, there is no reason why it could not work and such a ferry, modified by using horses, was used in lake champlain in 19th-century america. see "when horses walked on water: horse-powered ferries in nineteenth-century america" (smithsonian institution press; kevin crisman, co-authored with arthur cohn, executive director of the lake champlain maritime museum). see experiment (horse powered boat). ==notable services== ===europe=== the busiest seaway in the world, the english channel, connects great britain and mainland europe, sailing mainly to french ports, such as calais, boulogne, dunkirk, dieppe, roscoff, cherbourg-octeville, caen, st malo and le havre. ferries from great britain also sail to belgium, denmark, the netherlands, norway, spain and ireland. some ferries carry mainly tourist traffic, but most also carry freight, and some are exclusively for the use of freight lorries. in britain, car-carrying ferries are sometimes referred to as roro (roll-on, roll-off) for the ease by which vehicles can board and leave. [[file:silja symphony kustaanmiekka.jpg|thumb| leaving helsinki via the kustaanmiekka strait to t
Boat_types Ferries Ship_types