Vandestadt & McGruer was the Canadian importer of the American built MacGregor line of trailerable sailboats in early 1970s. The company also built the SIREN 17.
The SIRIUS 21/22 is said to be the first North American production-built, ballasted cruising boat with positive flotation. In a more expensive procedure, closed-cell foam was injected into some compartments, then into the gap between the inner and outer hull the full length and up to the deck level.
In the early 1980s, the hull was modified to include a reverse sheer transom at which point the boat was renamed the SIRIUS 22.
A fixed-keel model was also offered.