Battle of Iwo Jima: The Naval Campaign at Sea

The Marines who fought their way up Mount Suribachi and across the Motoyama plateau in February and March 1945 (see the Japanese defense of Iwo Jima) never left the beach without the US Navy putting them there and keeping them supplied. Operation Detachment, the codename for the invasion, was as much a naval campaign as a land battle: five numbered task forces, more than 500 ships, and a fast carrier force screening the whole operation from Japanese air power based on the home islands.

Task Force Organization

Admiral Raymond A. Spruance commanded the entire operation as head of the Fifth Fleet. Beneath him, Vice Admiral Richmond Kelly Turner commanded Task Force 51, the Joint Expeditionary Force, which held overall responsibility for getting the landing force ashore. Turner's subordinate commands split the work: Rear Admiral William H. P. Blandy ran Task Force 52, the Amphibious Support Force, responsible for minesweeping and pre-landing bombardment; Rear Admiral Harry W. Hill commanded Task Force 53, the Attack Force that actually embarked and landed the assault troops; and Rear Admiral Bertram J. Rodgers commanded Task Force 54, the Gunfire and Covering Force built around three battleship divisions, a cruiser division, and several destroyer divisions.

General Holland M. Smith commanded Task Force 56, the Expeditionary Troops (the V Amphibious Corps and its three Marine divisions), while Vice Admiral Marc A. Mitscher's Task Force 58, the fast carrier force, ranged well beyond the objective area to strike airfields on the Japanese home islands and screen the invasion fleet from air attack.

Blandy's Task Force 52 also carried an Underwater Demolitions Group, tasked with beach reconnaissance and clearing obstacles before the landing craft went in, work that had to be done close inshore and under fire in the days leading up to 19 February. On D-plus-1, two more cruiser divisions and two more destroyer divisions detached from Mitscher's Task Force 58 to reinforce Rodgers' gunfire force, a sign of how much close-in fire support the fighting ashore consumed once the Marines were past the beach.

The Bombardment Debate: Ten Days Requested, Three Given

Smith and Major General Harry Schmidt, commanding the V Amphibious Corps landing force, asked Spruance for ten days of direct naval gunfire against the island before the Marines went ashore. A later, scaled-down request asked for nine. Spruance authorized three, a decision driven by the competing demand to keep the fast carriers available for strikes on Japan and by an underestimate of how deeply Kuribayashi's garrison had dug in. Rear Admiral William Blandy's ships fired for three days beginning 16 February 1945, but of roughly 750 identified Japanese fortifications, fewer than 200 had been silenced by the time the landing began on 19 February.

D-Day and the Fire Support Ships

At 02:00 on 19 February, battleship guns opened the bombardment that marked the start of D-Day. Around 100 carrier and land-based bombers struck the island, followed by another round of naval gunfire, before the first of an eventual 30,000 Marines began landing at 08:30. Task Force 54's battleships, cruisers, and destroyers stayed on station through the following weeks to answer call-fire requests from Marines ashore, a role that continued long after the initial bombardment ended and proved far more useful than the brief pre-landing barrage had been.

The Kamikaze Attack of 21 February

Two days into the landing, Japanese aircraft based on the home islands struck the supporting fleet directly. On the evening of 21 February 1945, kamikaze aircraft hit the escort carrier USS Bismarck Sea, igniting fires that spread through stored torpedoes and ordnance; the ship rolled over and sank roughly two hours later, killing 318 of the 923 men aboard. It was the last US aircraft carrier lost to enemy action in the war.

The same evening, kamikaze aircraft struck the fleet carrier USS Saratoga off Iwo Jima, hitting her with bombs and suicide aircraft that wrecked her forward flight deck and holed her hull in two places. Saratoga suffered 123 dead and 192 wounded, lost 36 of her 70 aircraft, and had to withdraw to the US West Coast for repairs, though the ship survived and returned to service later in 1945.

Ships Named for the Battle

The Navy later named two amphibious ships for the island: the USS Iwo Jima (LPH-2), an amphibious assault ship that served from the Vietnam era onward, and the USS Iwo Jima (LHD-7), a Wasp-class assault ship commissioned decades later. Both carried the name into later conflicts far removed from the Pacific War; further detail on their operational history and on the wider order of battle for the ships at Iwo Jima is covered separately, alongside background on the island's pre-invasion preparations.

The island was declared secure on 26 March 1945, after five weeks of fighting that cost the Navy and Marine Corps close to 26,000 casualties. Its airfields were operational well before that: a damaged B-29, the Dinah Might, made an emergency landing on Iwo Jima before the battle had even ended, the first of thousands of B-29 crews who would use the island rather than ditch at sea over the following months.

For the Navy, Iwo Jima was as costly as any single Pacific operation of the war. Beyond Bismarck Sea and Saratoga, the amphibious and gunfire ships absorbed weeks of shore-fire and air attack while standing close offshore, a task that offered none of the maneuvering room a carrier task force normally used to reduce its exposure. Task Force 58's carriers, meanwhile, kept striking targets on the Japanese home islands throughout the operation, tying the Iwo Jima landing directly into the wider air campaign against Japan that the captured airfields were meant to support.