Ship's Keel
Fig. 167: Underwater view of a ship's keel with the propeller in the lagoon of Sabang. Dive #369: Sabang Laguna, Mindoro Island, Philippines. Nikon D200; Δt=1/160 s; f=10.5 mm; f/6.3; ISO 100; 15 November 2009 08:17:31