Tern sea terns have light grey or white body plumage as adults, with a black cap to the head. The legs and bill are various combinations of red, orange, yellow, or black depending on species. The pale plumage is conspicuous from a distance at sea, and may attract other birds to a good feeding area for these fish-eating species. When seen against the sky, the white underparts also help to hide the hunting bird from its intended prey. The Inca tern has mainly dark plumage, and three species that mainly eat insects, the black tern, white-winged tern, and black-bellied tern, have
SY Tern crank compression expansion engines providing 200 bhp to a twin screw propeller. She carried two masts and had an open navigating platform set forward of her amidships single funnel. She was also designed with a distinctive canoe-shaped bow. "Tern" has spent her whole active life operating on Windermere. She was caught in a severe storm while at Lakeside in November 1893 and sank at her moorings, but was refloated that night. In 1923 Furness Railway was absorbed into the London, Midland and Scottish Railway, as part of the measures of the Railways Act 1921, with "Tern" continuing to sail for