<P> In July, 2007, a hovercraft passenger service completed a two - week trial between Portobello, Edinburgh and Kirkcaldy, Fife . The trial of the service (marketed as "Forthfast") was hailed as a major operational success, with an average passenger load of 85 percent . It was estimated the service would decrease congestion for commuters on the Forth road and rail bridges by carrying about 870,000 passengers each year . Despite the initial success, the project was cancelled in December, 2011 . </P> <P> The inner firth, located between the Kincardine and Forth bridges, has lost about half of its former intertidal area as a result of land reclamation, partly for agriculture, but mainly for industry and the large ash lagoons built to deposit spoil from the coal - fired Longannet Power Station near Kincardine . Historic villages line the Fife shoreline; Limekilns, Charlestown and Culross, established in the 6th century, where Saint Kentigern was born . </P> <P> The firth is important for nature conservation and is a Site of Special Scientific Interest . The Firth of Forth Islands SPA (Special Protection Area) is home to more than 90,000 breeding seabirds every year . There is a bird observatory on the Isle of May . </P> <P> The youngest person to swim across the Firth of Forth was 13 - year - old Joseph Feeney, who accomplished the feat in 1933 . </P>

Where does the firth of forth meet the north sea