Zara - class cruiser The " Zara " - class was an Italian heavy cruiser design of the " Regia Marina " from the early 1930s , considered by many to be one of the best cruiser designs of World War II . Four ships of the class were completed , " Zara " , " Fiume " , " Pola " and " Gorizia " , all of which saw extensive service during the war . Design . The " Zara " s were essentially an improved " Trento " class tasked with dealing with the latest French designs . The " Trento " s had been designed to the limitations of the Washington Naval Treaty , which stated that cruisers had to be 10 , 000 tons or less , and armed with guns or smaller . The weight limitation made it impossible to design a ship with those guns " and " armour able to stop shells of the same caliber . A typical Washington design had 76 mm in its armour belt , and less on other areas of the ship . These thicknesses were reasonably good against destroyer and light cruiser weapons ( typically between 5 in { 127 mm } and 6 in { 150 mm } ) , but insufficient against the 120 kg shells that 203 mm fired , capable of piercing even 150 mm at medium range . In general , in order to be effective , armour should be roughly the same thickness as the diameter of the shells fired against it . " Trento " s had sacrificed armor for speed , allowing them to make high - speed dashes up and down the long Italian coastline , which would otherwise be difficult to defend from Italy ' s widely separated naval bases . Although equipped with powerful armament , hits against them would likely penetrate the armour and knock the ships out of combat . Even a won battle might seriously deplete Italian naval strength , something they were not prepared to address through sheer numbers . The solution was a new design , one combining the armament of the " Trento " s with the armour needed to protect them from similar French designs . To achieve this , the " Zara " s were almost 2000 t ( at standard displacement ) over the 10 , 000 ton limit , even if fully loaded ( because the modest amount of the fuel load ) they displaced no more than , for example , British heavy cruisers . Extras such as a high superstructure and torpedo tubes were removed in an effort to save weight , but in the end the ships ended up considerably " overweight " anyway . The removal of the superstructure made placement of radar difficult , and in the end none of the class would ever carry one . This would prove to be a fatal omission . Armour . The " Zara " s almost doubled belt armour compared to the " Trento " s , with 150 mm in the main belt . The main deck was also very thick , 70 mm . Turrets and barbettes were as well protected by over 100 mm armour . In addition to the primary armour scheme , there was secondary armour : the upper deck was 20mm , and the flank hull above main belt was 30 mm . Almost no other cruisers were equipped with two armoured decks and two armoured belts . This scheme followed , in fact , not quite a cruiser layout , but that of a small battleship . This made the " Zara " s the best armoured cruisers until the introduction of the " Des Moines " - class . This additional armour would have made the ships decidedly nose - heavy , so to offset this the rear of the ship was raised by one deck behind the front funnel . The result was excellent watertight integrity and protection . Armament . The " Zara " s shared their main armament with the last of the three " Trento " s , the " Bolzano " . They were equipped with the 203 mm / L53 ( 8 in ) guns of 25 tonnes each and were fitted in pairs in Ansaldo turrets . The guns had a high muzzle velocity of 939 m / s ( 3 , 080 ft / s ) with a 125 kg ( 275 lb ) AP shell , allowing " Zara " s to engage equals at a very long 34 , 400 yards ( 31 , 500 m ) at 45 elevation . The " Trento " and " Trieste " had a less advanced model , firing a 110 kg to 29 , 000 m . The downside to the new gun was a greater dispersion of shots and barrel wear than normal . The secondary armament was superior as well , compared to the standard of those times : sixteen Škoda Model 1910 100 mm / L50 guns were fitted in eight dual turrets , four on each side , again following a scheme similar to a small battleship . Later , these were replaced by OTO L / 47s , plus two single 100 mm mounts for flare illumination rounds . In 1937 , the aft 100 mm mounts were replaced by 37 mm / 54 caliber Bredas more useful for close defense , and in 1940 , the 40 mm Vickers were replaced by 37 mm Bredas , also . All these guns were reasonably modern , especially at their time , even if not outstanding performers . However , overall anti - aircraft performance was not good , due to the slow tracking process and an inadequate fire control system , although the weapons were acceptable . One odd feature was the aircraft catapult on the bow , which made it impossible to prepare for launch while firing , perhaps a minor consideration . The Piaggio P . 6 " bis " originally carried was later replaced by M . 41s , CANT 25AR s , MF6s , and in 1938 , by Ro . 43s . Service history . " Zara " was laid down at OTO Muggiano 4 July 1929 , launched 27 April 1930 , and commissioned 21 October 1931 . She was joined by " Fiume " , laid down at Stabilimento Tecnico Triestino on 29 April 1929 , launched 27 April 1930 , and completed 23 November 1931 ; " Pola " at OTO Livorno , laid 17 March 1931 , launched 5 December 1931 , and completed 21 December 1931 ; and " Gorizia " , launched 28 December 1930 at OTO Livorno . France immediately responded with a new heavy cruiser of her own , " Algérie " , which was a close match for the " Zara " s when she launched in 1934 . When the Second World War broke out , " Gorizia " , " Zara " , and " Fiume " were organized into 1st Cruiser division , " Pola " serving as flagship for 2nd Cruiser Division . During this part of the war , the " Zara " s were a serious problem for the Royal Navy , which had nothing comparable in the Mediterranean Sea , and were seriously outgunned by them during the inconclusive Battle of Calabria and Battle of Cape Spartivento . However , " Zara " s were eventually taken to task during the Battle of Cape Matapan . After " Pola " ( in company with " Fiume " and " Zara " , serving as escort to the battleship " Vittorio Veneto " ) was hit by a torpedo from a TSR Swordfish from " Formidable " , which stopped her , the rest of the 1st Division ( at this time " Gorizia " was in reserve ) ran in to protect her . Three Royal Navy battleships ( the " Queen Elizabeth " - class sisters " Barham " , " Valiant " , and " Warspite " ) , plus many supporting units , were able to approach them closely at night — the lack of radar on " Zara " s making them unaware of their approach . " Valiant " , astonishingly , scored with her first salvo . The British battleships quickly sank all three Italian cruisers and two of their escorting destroyer s in a one - sided gunfight , the only reaction being the aimless fire of a 40mm AA cannon from the already wrecked " Zara " . " Gorizia " survived until she was taken over by the Germans after Italy left the war in 1943 . In that year , her armour had the only opportunity to display its effectiveness , when this ship was hit by three bombs , launched by American bombers , but the main deck resisted them all and the ship continued to fire against the high - flying bombers . Later she was able to reach La Spezia , but the damage to the mid - ship was heavy , with almost all the structures over the armor belt devastated and a 100 mm ( 3 . 9 in ) turret thrown into the sea . Ironically , at beginning of 1941 , a modest British attack , at night , over Naples hit " Zara " . There were only two 113 kg ( 250 lb ) bombs , launched at low altitude , but they pierced the hull and almost sank the ship . " Gorizia " was sunk 26 June 1944 at her moorings in La Spezia , in yet another twist of fate by Italian manned torpedo es , after the Italians joined the Allies . Popular Culture . Two of the Class , the Zara and Pola , appeared in the alternate history Japanese anime Strike Witches 2 episode " Higher than the Sky " . The ships were recreated in detail with CGI animation technology .