Mirissa blue whale fluking behavior: tail fluke elevation and deep dive descent angles?

When Pygmy Blue Whales (Balaenoptera musculus brevicauda) feeding off Mirissa finish a series of surface breaths and prepare for a deep foraging descent down into the 1,500-meter Dondra submarine canyon, they exhibit a characteristic "fluking" sequence. The whale arches its massive caudal peduncle upward, lifting its wide triangular tail flukes completely out of the water and pointing them vertically toward the sky before sliding smoothly beneath the surface at a steep 75-degree downward angle. This vertical fluke lift provides maximum hydrodynamic leverage for deep vertical descent.