Mysteries abound in the sport of fishing because the elusive catch swims out of sight, down in the depths or near the surface, in early mornings, cool evenings or late at night. The pursuit is done by boat or beach, jetty, dock and everywhere in between. All ages try their luck, each cast of the rod a ray of hope, each tug on the line a pulse of possibility.

Opening day for the Martha’s Vineyard Striped Bass and Bluefish Derby is just a few weeks away, when all these factors and more come into play at a higher level as the stakes are high. Lines get wet at 12:01 a.m. on Sept. 15 and then it’s all in through Oct. 19.

This Saturday, in preparation for the Derby, or fishing in all manner, shape or form, the Martha’s Vineyard Surfcasters Association hosts its annual used tackle sale. All proceeds support scholarships for Island students.

The sale takes place from 8 a.m. to 1 p.m. at the Martha’s Vineyard Regional High School parking lot, where everything one needs to fish will be available, for the longtime angler or newbie still figuring out why those birds are circling over there. Rods, lures, reels, fishing gear for surf and boat and much more will be for sale at bargain prices.

Suit up and then head out to a favorite fishing hole. Two weeks of practice is all you have before it’s Derby go time.