There are fundamentally different in diving two different wing shapes. The Donat shape and the shape of a horseshoe.
Donat form - has bubble encircling Wing has the advantage that the buoyancy is supported in the hip area and thus a very strong and stable position in the water is guaranteed. The circumferential Wing bubble is very common.
Rotating Wing are blown Halcyon Evolve 40, Halcyon Evolve 60, Tecline Donut 15, Tecline Donut 17, Tecline Donut 22,
Horseshoe shape - the shape of the bubble-Wing, the buoyancy in the restricted Wing bubble pages on the Wing and blow the head area of the wing. This is the diver moving underwater.
Horseshoe shape Wing bubble - Halcyon Explorer 40, Halcyon Explorer 55