On their first day in the Baltic Sea last October, Lieutenant Commander Noel Lawrence and the crew of His Majesty’s Submarine E1 (see above) tried and failed to sink the German armored cruiser SMS Victoria Louise in Kiel harbor. Due to design problems that have since been fixed, their torpedoes ran too deep, but the trail of bubbles was still seen by sailors on deck, alerting the German Navy to the presence of British submarines. Winter iced over the Estonian port of Tallinn, where the E1 has been based with Russian support, and supply problems have prevented them from doing damage to the Germans all summer.

But Lawrence was able to damage the Moltke in August during the Battle of Moon Sound, and in September the British Navy’s undersea service was finally able to reinforce their Baltic flotilla. Despite losses, five boats have passed through the Öresund Strait, including the E19 under Lieutenant-Commander Francis Cromie, and now they are finally becoming active against German shipping.

Today, Cromie and his men are sailing off the Swedish island of Öland when they spot a German steamer and haul her over. The merchantmen abandon ship, but the rough seas prevent the E19 from sinking her. Despite this inauspicious first day of hunting, Cromie’s cruise proves to be a spectacular success tomorrow morning when he stops the SS Walther Leonhardt sailing home with a load of iron ore for the Kaiser’s hungry steel foundries; hauling her over, Cromie has his crew sink the ship with a scuttling charge, but they spot yet another steamer before she has finished slipping beneath the waves. It is the SS Germania, also carrying iron ore. Giving chase, the E19 fires several shells from her deck gun until the vessel runs aground in the shallows and is abandoned by her crew, whereupon Cromie attempts to sink her with dynamite, but fails.

It is still morning, and the day is hardly done, for this is one of the world’s busiest shipping channels.

The E19 and her crew in Harwich, UK. E-class boats were the most recent and advanced British submarine design

At about 1 PM, Cromie’s lookouts sight the SS Gutrune, their largest prize yet. Stopping the freighter, he orders its crew into their lifeboat and has his boarding party open the bottom valves and circulation pumps to let in the sea, sinking her quite slowly but without expending his limited weaponry. Before the Gutrune slips beneath the waves, another ship appears on the horizon, which turns out to be a neutral Swedish ship on its way to the Dutch port of Rotterdam, but Cromie has scarcely made this determination when he spots the SS Director Reppenhagen, which he sinks the same way as the Gutrune. Finally, at 5:30 PM the E19 stops the 360 foot-long SS Nicomedia, whose crew offers them a barrel of beer from their stores in hopes of persuading the British sailors to spare their vessel, but to no avail. In what becomes known to German merchant sailors as ‘the submarine massacre,’ Cromie’s command has sunk or incapacitated five ships in a single day without using any torpedoes.

One week later, Lieutenant Commander Max Horton and the E9 go on a similar rampage, hauling over and sinking four German ships in twenty-four hours. First is the SS Soederham; in a somewhat comic turn, the ship’s cargo of Swedish wood keeps her afloat even with scuttling charges blown and valves left wide open by the boarding party. After sinking the Pernambuco that evening, the E9 spends an uneventful night in international waters; early the next morning, her lookouts spot the collier SS Johannes Russ, and the E9 repeats what has now become a routine of stopping and inspecting the ship. Slow to sink, her crew is rescued by the Swedish destroyer Wale, which attempts to tow the stricken vessel to port; a tug arrives to take up the job, but an unexplained explosion finally sinks the ship and forces the tug’s crew to cut their tow line or be pulled under. By then, it is late morning, and the Wale has turned back out to sea in time to rescue the crew of the Hamburg-based collier Dalälfven, which Horton has chosen to sink with one of his pricey torpedoes.

While almost anyone who knows anything about the First World War knows of the German u-boat threat, the spectacular successes and great sacrifices of the British submarine fleet are much less well-known. Disdained by their own comrades on the surface when the war began, daring missions in the Dardanelles and the Sea of Marmara have covered the Royal Navy’s submariners in glory, and the Baltic campaign is cementing their place forever in the world’s proudest naval tradition.

The E9 photographed in 1914. British submarines will exact a heavy toll on Germany’s Baltic shipping