Sounds like a 25 year old regatta sail. Short mast and long boom with three short battens. Is the sail all Dacron (no plastic laminate on the sail), with a thick flexible window?
Given the mast and boom sizes, it my be around 5 - 5.5 meters. I still have my 1985 Superlight regatta sail and use it on the original board.
Are there any markings on the main body of the sail (numbers or a design)?
Any pulleys or just a grommet at the foot of the sail?
Formula 160; iSonic 111; HiFly Move 105; Tiga 263; '85 Mistral Superlight.
Maui Sails TR 11.0; 9.2; 8.4; 7.6; 6.6; Maui Sails Switch 6.0; 5.2; Maui Sails Global 4.5; 4.0.