During 1977-78, a conservation project was undertaken by the Federal Government of Canada to preserve the weathered hull of the HD-4, an experimental hydrofoil craft built at the laboratories of Alexander Graham Bell in Baddeck, Nova Scotia. After achieving a world marine speed record of 70-86 m. p.h. (114.01 km.p.h.) in 1919, the craft was beached on the shore of a salt water lake. Forty years'exposure to severe weathering caused wood rot, metal corrosion and the disintegration of the canvas covering. Due to the deteriorated condition of the craft and the loss of most of the external structures, complete restoration was not desirable or practical. The aim of the project was, therefore, to stabilize the wooden hull, while preserving its weathered appearance.