The Sun Fast 40' is a child of the earlier Janneau 40' from which it derives its hull but has an increased mast with 3 orders of spreaders and more weight at the bulb to be a competitive sailing boat. The interior, however, remains that of a fine cruising boat, and the double rudder wheel gives ease of rising from the sea and mobility in the cockpit.

Boat equipped with battened mainsail with trolleys, jib and gennaker (with bowsprit) has excellent performance under sail; all rigging is deferred to the cockpit where no less than 6 winches allow the boat to be steered safely; a generous 56Hp Yanmar engine allows her to motor transfers quickly and safely.

In the cockpit, two benches are on either side of a central table that allows outdoor dining for up to 6 people. 

The boat is licensed for unlimited offshore sailing and equipped with an ocean raft and all necessary equipment for navigation.

A tender with the latest electric motor completes the usability for sea bathing and shore excursions for visits to hidden bays.

The interior, all finished in wood, consists of: a large square (dinette) with sofa, central table, a side sofa, the "charting" area, and a bathroom with shower. From the central area of the boat there is access to three cabins with double beds: one in the bow, which is large and has a private bathroom, and two in the stern.