The term 'kind of sail' refers to the different types of sails used on boats. The three crossword solutions for this term are GAFF (4 letters), LATEEN (6 letters), and LUG (3 letters). GAFF sails are four-sided sails that are attached to a spar, or pole, and are typically used on larger boats. LATEEN sails are triangular sails that are attached to a long yardarm and are commonly used on smaller boats. LUG sails are four-sided sails that are attached to a yardarm and are often used on traditional fishing boats.