Commander Harry Lewin Lee Pennell was appointed a Midshipman in September 1899 and was commissioned Sub. Lieutenant in 1902. In 1910 he received Admiralty permission to join Scott's primarily scientific expedition to Antarctica as the Navigator of the half-Whaler, half-Steam Yacht Terra Nova. The veteran globe trotter and celebrated expedition photographer, Herbert G. Ponting, for one remembered Pennell in truly the best of terms:

'Harry Pennell, our Navigating Officer, was the most energetic man I have ever known. The end of the day's work that might well have wearied the hardiest, would find him fit and fresh as the beginning; and during the entire voyage, no matter how inclement the weather, he never slept elsewhere than wrapped up in blankets on the chart-table on the Terra Nova's Bridge. He seldom came below decks except for meals. When Pennell was not occupied with navigating problems, he was either on watch, or conning from the crow's nest, or else out on the yard-arms helping the seamen set or shorten sail, or otherwise assisting in the handling of the ship. He was a 'whale for work'. The services of this brilliant Officer were of inestimable value to the Expedition; for, after the exploring parties had been landed in the South, he was in command of the Terra Nova during her subsequent voyages. His quiet, modest unassuming manner only accentuated his obvious intellectual talents; and all his friends marked him out for a distinguished career. But, like so many others of Britain's finest and bravest he gave his life for his country five years later - in the North Sea, not far from where his friend Lieutenant Rennick died. He went down in H.M.S. Queen Mary, of which he was Navigating Commander, in the Battle of Jutland. Harry Pennell left a young bride to mourn him' (The Great White South refers).

Appointed Navigating Commander of the new Battle Cruiser Queen Mary, Pennell was fated to meet his end at Jutland with almost the entire Ship's Company on 31.5.1916. Following the chance encounter between H.M.S. Galatea and the German Light Cruiser Elbing, and the initial exchange between the opposing Battle Cruisers under the commands of Admirals Beatty and Hipper, there was confusion in the British fire orders, the signal flags from Beatty's Flag Ship not being seen by Queen Mary and Tiger owing to smoke. As a consequence there was an unequal distribution of fire, the German Battle Cruiser Derfflinger remaining immune from fire for ten minutes. Finally Queen Mary, under fire from the Battle Cruiser Seydlitz, realised the mistake and opened on Derfflinger who on the German side had made the same error. Minutes later she was hit at a range of 14,500 yards by a plunging salvo on the forward deck. An eye-witness in Tiger's conning tower reported:

'The Queen Mary was next ahead of us, and I remember watching her for a little and saw one salvo straddle her. Three shells out of four hit, the impression one got of seeing the splinters fly and the dull red burst was as if no damage was being done, but that the armour was keeping the shells out. The next salvo that I saw straddled her, and two more shells hit her. As they hit I saw a dull red glow amidships and then the ship seemed to open out like a puff ball, or one of those toadstool things when one squeezes it. Then there was another dull red glow somewhere forward and the whole ship seemed to collapse inwards. The funnels and masts fell into the middle, and the hull was blown outwards. The roofs of the turrets were blown 100 feet high, then everything was smoke, and a bit of the stern was the only part of the ship left above water. The Tiger put her helm hard-a-starboard, and we just cleared the remains of the Queen Mary's stern by a few feet'.