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The Gilbert Islands Operation (November 13 - December 8, 1943) marked America's first major Central Pacific offensive, launching the largest amphibious assault yet assembled in the Pacific theater with 35,000 troops aboard 17 aircraft carriers, 12 battleships, and over 200 vessels. This campaign earned veterans the Asia-Pacific Theater ribbon with campaign star, forever changing Pacific warfare strategy.
Operation Galvanic emerged from the Allied strategic need to establish a Central Pacific drive toward Japan, complementing MacArthur's Southwest Pacific offensive. The Gilbert Islands, comprising 16 coral atolls near the equator, served as the gateway to the Marshall Islands and ultimately the Mariana Islands.
"The capture of Tarawa knocked down the front door to the Japanese defenses in the Central Pacific." - Admiral Chester W. Nimitz
The campaign aimed to: • Establish airfields and naval bases for future Central Pacific operations • Neutralize Japanese air and naval threats to Allied supply lines • Create stepping stones for the planned Marshall Islands invasion • Divide Japanese attention between multiple fronts
Campaign Duration: November 13 - December 8, 1943 Primary Operations:
|
Date |
Event |
Location |
|
November 13, 1943 |
Pre-invasion bombing begins |
Makin and Tarawa |
|
November 20-23, 1943 |
Battle of Tarawa |
Betio Island, Tarawa Atoll |
|
November 20-24, 1943 |
Battle of Makin |
Butaritari Island, Makin Atoll |
|
November 21-24, 1943 |
Abemama Island operations |
Abemama Atoll |
|
December 8, 1943 |
Campaign officially concluded |
Gilbert Islands |
Admiral Chester W. Nimitz
Vice Admiral Raymond A. Spruance
Rear Admiral Richmond Kelly Turner
Major General Holland M. "Howlin' Mad" Smith, USMC
Major General Julian C. Smith, USMC
Major General Ralph C. Smith, USA
Rear Admiral Harry W. Hill
2nd Marine Division (Tarawa)
27th Infantry Division (Makin)
The American invasion force represented the largest yet assembled for a single Pacific operation, consisting of 17 aircraft carriers (6 fleet aircraft carriers, 5 light aircraft carriers, and 6 escort carriers), 12 battleships, 8 heavy cruisers, 4 light cruisers, 66 destroyers, and 36 transport ships.
Fleet Carriers:
Light Carriers:
Escort Carriers:
Battleships:
American Aircraft: • F6F Hellcat fighters • SBD Dauntless dive bombers • TBF Avenger torpedo bombers • B-24 Liberator heavy bombers (over 100 aircraft from Seventh Air Force) • PBY Catalina amphibians (24 aircraft) • Ventura twin-engine bombers (24 aircraft)
Landing Craft and Vehicles: • Amphibious tractors (amphtracs) - new tracked landing vehicles carrying 20 troops each with machine guns • Higgins boats (LCVP) • USS Ashland (LSD-1) - first dock landing ship
Rear Admiral Keiji Shibazaki
Lieutenant Junior Grade Seizo Ishikawa
Tarawa Atoll (Betio Island)
Total Strength: Nearly 5,000 Imperial Japanese Naval Landing Forces (3,000 Special Naval Landing Forces and 1,247 construction laborers)
Key Units:
Total Strength: 798 Japanese troops, including 276 laborers and 100 aviation personnel
Tarawa (Betio Island) Defenses
Betio was the most fortified atoll America would invade during the Pacific Campaign, measuring around two miles long and a half-mile wide, crisscrossed with defenses:
Fortifications: • 100 pillboxes (dug-in concrete bunkers) • Extensive seawalls • Complex trench systems for defensive movement • Central airstrip (Hawkins Field) • Underground command bunkers and shelters
Weapons Systems: • Coastal defense guns • Anti-aircraft guns
• Heavy and light machine guns • Light tanks • Beaches naturally ringed with shallow reefs, covered with barbed wire and mines
Makin Island Defenses
Lieutenant Junior Grade Seizo Ishikawa ordered extensive fortifications including several 8-inch (203 mm) coastal defense guns, 1.5-inch (38 mm) anti-tank gun positions, machine gun emplacements, rifle pits, and 15 feet (4.6 m) deep tank barriers with anti-tank guns and barbed wire.
Defensive Barriers: • Western tank barrier: 12-13 feet wide, 15 feet deep • Eastern barrier: 14 feet wide, 6 feet deep • Reinforced with concrete, barbed wire, and gun positions
The Amphibious Assault
On November 20, 18,000 U.S. Marines sent to tiny Betio were expected to easily secure it; however, problems quickly arose when low tides prevented landing crafts from clearing the coral reefs.
"The water seemed never clear of tiny men.... They kept falling, falling, falling... singly, in groups, and in rows." - Naval observer describing the Tarawa landing
Day 1 (November 20): • At 0441, Japanese coastal guns opened fire • Marines forced to wade 700 yards to beach under heavy fire after landing craft stranded on reef • General Julian Smith reported "issue in doubt" to his superior • Marines established tiny beachheads on Red Beach 1, 2, and 3
Day 2-3 (November 21-22): • Reinforcements landed successfully • Marines advanced toward central airstrip • Sherman tanks supported ground assault • Japanese defense began to collapse
Final Day (November 23): • By early afternoon, American lines reached the eastern tip of Betio, and the island was declared secure • Of the Japanese garrison, 4,690 were killed; 17 soldiers and 129 laborers were captured
Casualties and Impact
American Casualties: • More than 1,000 U.S. troops killed in action and some 2,000 wounded in only three days • Of the 1,021 U.S. personnel killed during the Battle of Tarawa, approximately 350 remain unaccounted-for
The Army 27th Division, a National Guard unit from New York, landed on Butaritari with rather small casualties, taking two days to clear defensive barriers at the cost of 66 deaths with an additional 152 wounded.
Key Differences from Tarawa: • Lighter Japanese resistance (798 defenders vs. 4,500 at Tarawa) • More successful landing operations • Completed by November 23, 1943
A detachment of 300 soldiers from Tarawa had occupied Abemama in September 1942, but by November 1943, most Japanese soldiers had been evacuated, leaving only 25 Special Naval Landing Forces. Marines called in fire support from USS Nautilus, and the next morning discovered that Nautilus guns had killed 14 Japanese and the rest had committed suicide.
Admiral Nimitz launched the Marshalls campaign ten weeks after the seizure of Tarawa. Aircraft flown from airfields at Betio and Abemama proved highly valuable.
Key Outcomes: • Established first permanent Central Pacific bases • Proved viability of amphibious assault doctrine • Led to founding of Underwater Demolition Teams (UDT) - precursor to U.S. Navy SEALs • Generated crucial lessons for future atoll warfare
Tactical Improvements for Future Operations: • Need for accurate tide tables and hydrographic reconnaissance • Requirement for sustained preliminary bombardment • Importance of sufficient amphibious vehicles • Better waterproofed communications equipment • Improved equipment development, including better-waterproofed radios
Public and Political Impact
The heavy casualties suffered by the United States at Tarawa sparked public protest, where headline reports of the high losses could not be understood for such a small and seemingly unimportant island. However, military leaders defended the operation's strategic necessity.
Sergeant William J. Bordelon, USMC
USS Liscome Bay Tragedy USS Liscome Bay was sunk November 25, 1943, off the Makin Atoll by Japanese submarine attack, representing one of the campaign's most significant naval losses.
|
Category |
United States |
Japan |
|
Total Personnel |
~35,000 |
~6,300 |
|
Major Warships |
200+ vessels |
Minimal naval presence |
|
Aircraft |
900 |
<100 (mostly destroyed pre-battle) |
|
Campaign Duration |
25 days |
Defensive operation |
Battle Casualties Summary
|
Battle |
US KIA |
US WIA |
Japanese KIA |
Japanese POW |
|
Tarawa |
1,021 |
2,101 |
4,690 |
146 |
|
Makin |
66 |
152 |
~550 |
105 |
|
Abemama |
0 |
0 |
~25 |
0 |
Amphibious Warfare Advances: • Introduction of amphtracs (amphibious tractors) capable of crawling over shallow reefs • Coordinated "Atoll War" tactics combining naval gunfire, air support, and ground assault • Improved ship-to-shore communication systems
Japanese Defensive Innovations
Fortification Techniques: • Deep bunker systems resistant to naval bombardment • Interlocking fields of fire across landing beaches • Strategic placement of obstacles and barriers • Sophisticated defensive structures designed to stop attackers in the water or pin them on beaches
The Gilbert Islands Operation fundamentally altered the Pacific War's trajectory by:
• Establishing the viability of Central Pacific offensive operations • Creating the infrastructure for subsequent Marshall Islands invasion • Demonstrating American industrial and military superiority • Enabling the two-pronged assault on Japan that characterized the war's final phase
Veterans of the Gilbert Islands Operation earned the right to wear a campaign star on their Asia-Pacific Theater ribbon, recognizing their participation in this pivotal campaign that opened the Central Pacific route to Japan.
Primary Sources
Secondary Sources
Additional Reading Materials
Online Resources
