When it was available the aircraft was supplied as a kit or in the form of plans for amateur construction.
[1] The aircraft features a cantilever strut-braced triplane layout, a single-seat, with an optional two-seats-in-tandem open cockpit, fixed conventional landing gear and a single engine in tractor configuration.
[1] The St Croix Sopwith Triplane differs from the original 1916 design in that it employs a welded steel tube fuselage, modern engine installation and other minor details.
With full fuel of 35 U.S. gallons (130 L; 29 imp gal) the payload for the pilot, passengers and baggage is 315 lb (143 kg).
[1] The manufacturer estimated the construction time from the supplied kit as 4000 hours.