The Nimrod Mk II entered service 88 years ago. Compared to the Mk I, all Mk IIs had an arrestor hook for carrier operations. The Mk II also had slightly swept back wings, a larger tail, and a better engine. Just 30 were built with more made via upgrades to Mk Is. http://pbs.twimg.com/media/FiVr19MaEAA0I97.jpg