Diller & Schwill

Diller & Schwill was the Canadian naval architecture and boatbuilding partnership of John Diller and Herman Schwill, formed in 1971 in Odessa, Ontario, to design and produce affordable, trailerable fiberglass sailboats for the recreational market. Diller, a Queen’s University-trained naval architect, focused on stable, high-freeboard hulls with shoal-draft keels, while German-born Schwill, a master fiberglass craftsman, ran DS Yachts (Schwill Yachts) with hand-laid construction and practical interiors. Their DS-16 (1971), DS-20 (1972, ~160 built), and DS-22 (1975) became Great Lakes favorites for ease of towing, family-friendly stability, and low-cost cruising, with the DS-20’s Mark II adding a galley and improved berths. Operating until 1983, the duo dissolved after Schwill’s retirement, but their boats—known for durability, simple masthead rigs, and PHRF 250–300 performance—remain active in Ontario and U.S. fleets, influencing modern trailer-sailers like the Precision 21.