Its MK III Mod. Durable and reliable, this clinometer is required on all Naval vessels. 11.75″ x 7″. Our items are available for pick-up. No additional information at this time. You might also like. USS Sea Lion (SS-195) Submarine. French Naval Cutlass, model 1803. USS Greenfish (SS-351) Submarine. USS Steelhead (SS-280) Submarine.