Waterproof slide fastener

A waterproof slide fastener comprising:

• a pair of tapes;
• a plurality of coupling elements attached to one side of the pair of tapes;
• and
• a pair of coatings of polymeric material provided on an other side of the pair of tapes, respectively, and extending continuously along a longitudinal direction of the pair of tapes, wherein
• when the waterproof slide fastener is in an open state, when seen in a cross-sectional view taken along a width direction of the pair of tapes, each of the coatings gradually increases in thickness thereof toward the coupling elements to comprise a fin with an expanded shape,
• when the waterproof slide fastener is in the open state, when seen in the cross-sectional view taken along the width direction of the pair of tapes, each fin comprises a rising portion extending away from the coupling elements in a front and back direction of the pair of tapes from an end edge of each of the tapes as a start point, a top portion being continuous to the rising portion and a return portion being continuous to the top portion and extending away from the coupling elements in the width direction of the pair of tapes, and
• when the waterproof slide fastener is in the open state, when seen in the cross-sectional view taken along the width direction of the pair of tapes, the coupling elements attached to one of the tapes separate from the coupling elements attached to the other of the tapes, each of the coatings extends beyond an end edge of the respective tapes, each of the coupling elements extends beyond an end edge of the respective coatings which is defined between the rising portion and the top portion, in the width direction of the pair of tapes, the coupling elements attached to one of the tapes extend beyond the end edge of one of the coatings on the one of the tapes, and the coupling elements attached to the other one of the tapes extend beyond the end edge of the other one of the coatings on the other one of the tapes.