Three-Masted Schooner Sailplan
Schooners are fore-and-aft rigged sailing vessels with at least two masts; the after mast is the same height or taller than the foremast. Three-masted schooners were also called tern schooners. The only 7 masted schooner was the Thomas W. Lawson. More commonly found in the latter half of the 19th and early 20th century coastal trade were 4 and 5 masters. A few six masters were built.
The diagram is from the Nova Scotia Museum Informational poster, Sailing Ship Rigs.