A replacement rudder for Native Watercraft. This one is designed for a Mariner 12.5, but may fit others. Features an easily replaceable rudder blade so you can switch it out for a larger rudder if desired. Uses 2 x 20mm, m5 stainless bolts to hold the fin to the shaft.
The designed rudder blade has a lot more area than the original design, so your kayak should turn faster.
Print the shaft flat side down and the fin vertically. I used PETG for strength and flexibility.