OverBoard 25-Liter Waterproof Backpack for $34.92. Shipping is $4.95, which comes to a total of $39.87 shipped. This waterproof backpack floats and is waterproof to 3 feet. It features padded shoulder straps, padded back, padded lumbar, adjustable sternum strap, adjustable waist belt, top carry handle, outer elasticized bungee, and two outer elasticized mesh pockets. This backpack usually sells for about $70. Valid on 4/27 only.