They may be indexing points, I don't know a lot about molding rubber and why or why not you would need to have those, but I can tell you one thing... I can tell you what you can say they do.
They are ambient pressure sensing ports which conduct the exact pressure at any given depth towards the center of the fin. Pressure imbalances cause movement of the fin, and/or the water around the fin. Undesired pressure imbalances cause undesired movement. By placing these sensors in both the top and botttom of the fin, ambient pressure is balanced.
They are ambient pressure sensing ports which conduct the exact pressure at any given depth towards the center of the fin. Pressure imbalances cause movement of the fin, and/or the water around the fin. Undesired pressure imbalances cause undesired movement. By placing these sensors in both the top and botttom of the fin, ambient pressure is balanced.
