I begun pondering a big Delta fin for my big board with Decrepit the other day and I need to pick the brains of those who now a lot more about aerodynamics/hydrodynamics than I do.. Question - I notice the MUF Delta fins are the classic Mirage jet fighter straight leading edge shape. However Concorde had a concave curve leading edge. Whats the advantage of a straight leading edge in terms of lift/drag, if there indeed is one?