Most pedal drive kayaks have some type of splash shield incorporated in the design to keep water from churning up through the hull. The Riot Mako and the Lost Creek kayak models use a curved plastic piece mounted to the drive itself to minimize this water splash. The shield is effective, but isn't real thick and can be broken if you set the drive down the wrong way or something hits it.
Some tape or glue might get you a temporary fix, but you will eventually want a replacement, and this is it. This one fits the 10' and 12' model kayaks; the 14 and inflatable models sizes are larger (not yet available as a replacement item).
We sell Riot kayaks and other brands at our retail stores in Arizona, and ship kayaks to customers throughout the Lower 48.