Fisly CLASS 5 specifications are described in the International Rules, Appendix 2 C 1

1.1.The minimum weight of the fully rigged yacht is 50 kg.
2.1.The boom must be made of round section straight metal tube(s).
2.2.The lowest point of the boom must never come under 45 cm from the ground or the eyes level whichever is the highest. There must be a device that make it impossible to sheet any part of the boom below this level. A note is made for future checking and the position at which the measurement was made is marked on the yacht and the boom.
3.1.The width of the yacht should not exceed 2 000 mm.
3.2.The wheelbase of the yacht must not exceed 2 500 mm.
3.3.The chassis must be made of metal tubes, the section of which must be round, square or rectangular.
Cables are forbidden, except for the stearing.
3.4.Fairings are forbidden on the chassis, inside and outside. Wheel covers are allowed.
3.5.Any wheel with wire spokes must be covered by internal and external wheel covers.
3.6.Maximum diameter of the wheels including the tyre must not exceed 750 mm. the wheel alone shall not exceed 26.
The wheel width shall not exceed 100 mm measured to the outside dimensions of the wheel rim.
3.7.Traveller are prohibited on the yacht.
4.1.The mast must be made of round section metal tube, the outer diameter of it must not exceed 60 mm.
4.2.The mast may be made from a maximum of four different diameter tubes, each tube must have a constant outer diameter and wall thickness over its full length. At each diameter change, 30 mm are free to allow for chamfering for protection of the mast pocket.
4.3.The mast must be rigidly supported by an arrangement of metal tubes, all not higher than 1 200 mm above ground level.
4.4.The position of the mast must not be modifiable while the yacht in motion.
4.5.The length of the mast shall be such that the distance from the top of the mast to its foot plus the distance from the mast foot to the ground shall not exceed 5,50 m.
5.1.The maximum profile area of the sail must be 5,50 m².
5.2.The sail must be located onto the mast by means of a pocket.
5.3.Mast pocket is maximum 40 cm when laid flat on the floor measured to the front of the mast pocket.
Inflation system of the mast pocket are forbidden. It must be closed except for mast entrance and exit.
5.4.Mast pocket must lay flat when placed on the floor.
5.5.The sail must be free to rotate around the mast.
5.6.The mast pocket must be made of sailcloth. Stiffeners, fairing, or similar devices fitted inside or outside the mast pocket are prohibited.
5.7.Fairings or similar devices fitted to the sail are prohibited.
5.8.The sail may be modified by a device as follows :
  1. Cunningham hole
  2. Foot tensioner
  3. Kicking strap
  4. Batten tensioner line or leach line.
5.9.The maximum width of the battens is 25 mm (including protections cap) and maximum thickness is 20 mm.
5.10.Maximum number of batten is 10.
5.11.Split batten are prohibited.
5.12.Batten (it) must also not have any mechanical hinge or shaping device.
5.13.The battens must be not closer than 8 cm to the front of the mast pocket.
6.1.The yacht must have a backrest and side restraint for the pilot and a footrest these accessory must be part of the seat.
The seat may not contribute to the rigidity or the resistance of the chassis.
6.2.The footrest should prevent the pilot feet to inadvertently touch the ground.
6.3.The external width of the seat must not exceed 1000 mm.
6.4.The external length of the seat must not exceed 2500 mm.
6.5.The front of the seat or footrest may not be further forward than the back of the mast.
6.6.Fairings that form part of the seat and extend no further than the limits of the seat are permissible.
The shape of the seat must be such that the pilot body is always fully exposed when viewed from above.
6.7.It shall not be possible to move the seat while the yacht is in motion.
6.8.Any sharp edges on the yatch must be made safe.
6.9.The yacht must have an effective brake.