Speed sailing in shallow water has become quite popular where a bank is not available. This also applies to places where the bottom is uneven and there are sandbars which can be difficult to navigate. Often seagrass or algae is attached, and even protrudes from the surface, resulting in mirror flat water, ideal for speed sailing. For these applications, extreme rake is required - firstly for safety, and secondly for reduced drag from weed/algae contamination. If a sandbar is encountered, the extreme tip rake of these specialised fins significantly reduces the impact loads and saves catapults.
We looked at the locations, and the requirements to suit this style of sailing afforded by shallow seaweed beds. The challenges include the extra drag and erosion when cutting through surface type seaweed, starting in shallow water where the fin is likely to drag along the bottom, and the extreme rake causing problems with balance and power. We engineered the fin to simultaneously consider these constraints, and the design shape is unique as a result.