Simply purchase a MarCum or ShowDown brand sonar, and you receive a $50 or $25 prepaid VISA card. Buy a MarCum LX-3 or LX-5 Sonar by February 15, 2012, then simply fill out and return the MarCum BIG REWARDS form post-dated by March 1, 2012, and you’ll receive a $50 VISA prepaid card by mail. Purchase of a ShowDown 5.6 or 5.6 Dual Beam Sonar nets you a $25 prepaid VISA card (same dates apply.)