Airfields •
Falalop Airfield, now
Ulithi Airport, on Falalop Island, built by Japan, but abandoned, improved by Navy Seabees. A single runway spanning the entire width of the island. US Marine Air Group 45 (MAG-45), VMSB-24, and Service Squadron 45 with its headquarters were stationed at Falalop. MAG-45 and VMSB-24 flew missions to Japan's bases on Yap Island,
Fais Island and Sorol Island, with their
Grumman TBF Avenger,
Grumman F6F Hellcat and
Curtiss SB2C Helldiver. MAG-45 also flew anti-submarine patrols to protect Ulithi. The Marine Avengers sank two of the midget subs, only one sank a ship, a US Navy oiler at Ulithi. • Sorlen Airfield on Sorlen Island, Built by Seabees, an airfield for light aircraft. Started 12 December 1944, and completed January 27, 1945. • Mogmog Airfield, light aircraft, built on Mogmog Island to support the Mogmog Island Seabee camp and the Mogmog Island recreation center. Seabess started building on 12 December 1944 and completed on 27 January 1945. • At the three airfields the Navy kept up to 150 aircraft fighters to replace any lost on aircraft carriers. • Mogmog seaplane base, a floating seaplane base, supported by seaplane tenders. • Falalop Seaplane base on Falalop Island and in the atoll. Falalop Island base built starting 4 November 1944 and completed 5 December 1944 •
Fais Airfield is to the east of Ulithi by 87 km (54 miles) on
Fais Island. Ulithi supported the 3,000 feet runway built there in 1945. The runway was mostly used as an emergency landing strip.
LORAN station The
United States Coast Guard built a
LORAN (Long Range Navigational Signal) station at Ulithi in December 1944 and operated the station on Potoangroas Island till February 1945. For the
Korean War the LORAN station was moved to Falalop Island near the Falalop Airfield, as Potoangroas Island was only resupplied by sea, and in rough weather there was no resupply. The Ulithi LORAN Station was closed in February 1962 and moved to Yap Island. In 1978 the
Global Positioning System replaced the need for LORAN.
Mogmog Island US Navy Seabees turned the swamps and forest on Mogmog Island (Mog Mof) into a large
Ulithi fleet recreation center. The Seabees built the Ulithi Seabees camp with barracks and depot. At the depot Seabees stored all the supplies and gear needed to build and maintain the base at Ulithi. The Mogmog Island recreation center had a
bandstand, a refreshment center, a 1,200-seat theatre with a 25-by-40-foot stage, a sport center with 4 baseball diamonds and 200-seat chapel. The recreation center could house up to 8,000 men and 1,000 officers daily. Mogmog Island had a large recreation beach resort for those on leave. The Navy had an
ice cream barge that could make up to 500 gallons of ice cream for the troops in 8 hours. The barge would also make fresh bread products. The base officer's and chief petty officer's club was built on Mogmog Island. Mogmog Airfield was constructed for light aircraft for short trips to the other nearby islands. Off the shore of Mogmog Island in the atoll was the Mogmog floating seaplane base, supported by seaplane tenders.
Asor Island Naval Base Ulithi headquarters and the military cemetery were built on Asor Island. The 6th Special Naval Construction Battalion was in charge of most burial details. The 63 men lost during the attack on the USS Mississinewa AO-59, were given interment at Ulithi cemetery, as were some of those lost on the USS Franklin. After the war the cemetery was closed as the troops were reinterred in new, permanent cemeteries in the states.
Sorlen Island On Sorlen Island a second and small fleet recreation center was built. The main part of the recreation center was the 1,600 seat movie theater. A distillation center and 5,000-gallon storage tanks system was built to make freshwater. While the US Marine fighter base was on Falalop Island, a camp for Marine aviation was built on Sorlen Island, with barrack and mess halls. Naval Base Ulithi had many landing craft used to move gear and personal from ship to ship and ship to shore. On Sorlen Island a large landing craft camp was built. The Fifth Fleet and Third Fleet had hundreds of landing craft used in amphibious landings, that also use the camp and depot for maintaining the crafts when needed. A
quonset naval hospital was constructed on Sorlen Island with a 100-bed unit. A power plant was built to supply electricity. Seabees built the Sorlen Airfield for small plane use.
Submarine base Many US Navy
submarines were used in the Pacific War. The submarines attacked
warships and sank supply ships that were needed by Japan to resupply their many bases in the Pacific. US subs also did reconnaissance patrols, landed
guerrilla special forces and
search and rescue missions for downed aircrew men. US submarines had long ranges, but needed to be resupplied with fuel, food,
torpedoes and
deck gun shells. At Naval Base Ulithi the Navy set up a floating submarine base in the
atoll. The
submarine tenders
USS Sperry (AS-12) and
USS Sumner (AGS-5) were stationed in the atoll to supply the submarines. While the submarine was being resupplied, and repaired if needed, crews could have a break (
R&R) at the Ulithi's fleet recreation center on Mogmog Island. Some of the subs stationed at the base were:
USS Albacore (SS-218),
USS Skate (SS-305), and
USS Flying Fish (SS-229),
Repair depot The US Navy set up a large ship and boat repair depot at Naval Base Ulithi. The repair depot provided the fleet with support to keep
ships and
subs tactically available in the Pacific War with the repair and supply depot, rather than ships having to return to
continental United States. The Navy had built special
auxiliary floating drydocks that were able to repair battle damage to even the largest ships and do regular maintenance in the field saving ships trans-pacific travel time for repair. Supply store ships were also at the base with the parts needed to keep the fleet ready. The most noted ship repaired at the depot was the
USS Franklin (CV-13). The USS Franklin on 19 March 1945 was hit by Japanese bombs off Okinawa. Fire and explosions damaged the ship, killing and wounding many. The crew was able to save the badly damaged ship. Under her own power, she made it to Ulithi repair depot for emergency repairs before going to the
Brooklyn Navy Yard for a year-long complete rebuild. The
USS Houston (CL-81) and
USS Reno (CL-96) also had emergency repairs at Ulithi.
USS Hancock (CV-19) and
USS Ticonderoga (CV-14) were repaired at the base after kamikaze attacks. The
USS Bennington (CV-20) was repaired with a badly damaged flight deck from Typhoon Cobra. • Some of the Ulithi repair depot ships and crafts: •
USS AFDB-2, very large Auxiliary floating drydock able to repair
battleships •
USS Richland (YFD-64), Auxiliary floating drydock •
USS Oak Ridge (ARDM-1), Auxiliary floating drydock •
USS Endurance (ARDM-3), Auxiliary floating drydock • AFDL-32, a type of
Small Auxiliary Floating Dry Docks • USS ARD-13,
ARD Auxiliary floating drydock, mostly destroyer repair • USS ARD-15, ARD Auxiliary floating drydock, mostly destroyer repair • USS ARD-23, ARD Auxiliary floating drydock, mostly destroyer repair •
USS Jason (AR-8),
large repair ship •
USS Ajax, large repair ship •
USS Nestor (ARB-6), repair ship and small craft tender •
USS Oceanus (ARB-2), battle damage repair ship •
USS Vestal, large repair ship •
USS Mona Island (ARG-9), repair ship and
flagship for
MinRon 10 •
USS Deliver (ARS-23),
rescue and salvage ship •
USS Shackle (ARS-9), rescue and salvage ship •
USS Fortune (IX-146), an aircraft stores ship. Fleet issue ship effective 10 January 1945. •
USS Supply (IX-147), an aircraft stores ship for the land-based Marine Aircraft Group (MAG-45). •
USS Grumium (IX-174), an aircraft stores ship. • YRB-34, Floating Workshop
Seaplane bases seaplane crew seaplane in flight a seaplane tender. The crane at the rear of the ship is used to bring a seaplane on to the deck for repair and serving. The remaining parts of the ship are for the ship's and seaplane crew, also the ship's and seaplane fuel. The ship's stores would have crew's food and spare parts for seaplanes. The US Navy set up a two large seaplane base at Naval Base Ulithi,
Falalop seaplane base and
Mogmog seaplane base. Seaplanes did reconnaissance patrols and search, also rescue missions for downed aircrew and survivors of sunk ships. The most common seaplanes at the base were
Consolidated PBY Catalina and
Martin PBM Mariner. The Mogmog seaplane base take off and landing was a spot marked in the atoll off the fleet recreation center on Mogmog Island. The seaplanes were supported by a floating base of
seaplane tenders. The second seaplane base was on Falalop Island. On Falalop Island a seaplane ramp was constructed by the Seabees at one end of Falalop airfield. The seaplane ramp extended from the extreme low tide mark to the seaplane parking hardstand. The Falalop seaplane base was completed on 5 December 1944. Seaplane tenders and land base had stores to supply: food, fuel, ammo, spare parts. The seaplane tender also had housing and
mess halls for the aircrew while the seaplane was being serviced. Aircrew on leave could go to Ulithi's fleet recreation center on Mogmog Island. Some seaplane tenders were stationed at Ulithi seaplane base for months. Other seaplane tenders came to Naval Base Ulithi to resupply the ship's stores before returning to a
US Naval Advance Base. Some came to Ulithi repair depot to be repaired. Some seaplane tenders at Naval Base Ulithi: •
USS Corson (AVP-37) •
USS Hamlin (AV-15) •
USS Casco (AVP-12) •
USS Suisun •
USS Chandeleur (AV-10) •
USS Mackinac (AVP-13) •
USS Barataria (AVP-33) •
USS Chincoteague (AVP-24) •
USS Kenneth Whiting (AV-14) •
USS Onslow (AVP-48) •
USS Pocomoke (AV-9) •
USS St. George (AV-16) •
USS Duxbury Bay (AVP-38) •
USS San Pablo (AVP-30) •
USS Yakutat (AVP-32) •
USS Cumberland Sound (AV-17) •
USS Shelikof (AVP-52) •
USS Coos Bay • YSD-42 Seaplane Wrecking
Derrick • UN Navy seaplane Squadrons based at Ulithi seaplane base: •
VPB-13 with Consolidated PB2Y Coronado •
VPB-17 with Martin PBM Mariner •
VPB-18 with Martin PBM Mariner •
VPB-20 with Martin PBM Mariner •
VPB-23 with Consolidated PBY Catalina •
VP-41 with Martin PBM Mariner •
VP-42 with Martin PBM Mariner •
VP-48 with Martin PBM Mariner •
VPB-202 with Martin PBM Mariner
Submarine chaser base To help protect the base and shipping around the base, Naval Base Ulithi had a fleet of
submarine chasers. The submarine chasers were supported by a submarine chaser tender ship: the
USS Mindanao (ARG-3) was stationed at Ulithi to support the fleet of submarine chasers and some
crash boats.
crash boats were fast boats use to rescue downed airmen. Some of the submarine chasers that served at Ulithi:
USS PC-1137,
USS PC-598,
USS PC-1136,
USS PGM-18, and
USS PC-1138.
Destroyer base , a destroyer tender, with
destroyer escorts during World War II Hundreds of US Navy
destroyers were used in the Pacific war. Destroyers were used to protect
capital ships like
aircraft carriers,
battleships and
heavy cruisers. Destroyers were used to screen and protect
convoy of ships. Destroyers were used to hunt submarines and protect
amphibious landings at beaches. Destroyers had
anti-aircraft guns,
radar, and
forward-launched ASW weapons,
dual-purpose guns,
depth charges, and torpedoes. Like the submarines, they needed to be restocked with food, fuel, supplies, and
weapons to be kept operational. Ulithi had a large destroyer base, with
destroyer tenders. Destroyer tenders could do minor repair work on the ships also, and major work could be done at the Ulithi repair depot. Destroyer tenders stationed at Ulithi: •
USS Cascade (AD-16) •
USS Prairie (AD-15) •
USS Piedmont (AD-17) •
USS Yosemite (AD-19) •
USS Hamul (AD-20) to support Okinawa campaign damage •
USS Dixie (AD-14) September 1944 to February 1945 •
USS Sierra (AD-18) 15 March 1945 to 25 May 1945 •
USS Markab Floating hospital For four months (March to June) in 1945 Naval Base Ulithi was used as a major forward Naval hospital. US Navy
Hospital ships were stationed Naval Base Ulithi during parts of the war and some were stationed shortly as they joined staging for upcoming invasions. Hospital ships also were able to resupply and refuel at the base. •
USS Relief (AH-1), 550-beds, stationed at Ulithi two times, received wounded from USS Randolph. •
USS Mercy (AH-8), up to 400 patients, stationed at Ulithi 5th Fleet to care for wounded from
Battle of Okinawa. •
USS Samaritan (AH-10) up to 394 patients, stationed at Ulithi two times. •
USS Rescue (AH-18) up to 800 patients, was stationed at Ulithi in March 1945 before going to Okinawa. •
USS Solace (AH-5) up to 418 patients, stationed at Ulithi two times, was stationed at Ulithi in March 1945 before going to Okinawa. •
USS Tranquillity (AH-14) up to 802 patients, stationed at Ulithi near the end of war, departed Ulithi to help survivors from the
USS Indianapolis (CA-35) sinking. •
USS Hope (AH-7), up to 400 patients, was stationed shortly at Ulithi in March 1945 before going to Okinawa. •
USS Bountiful (AH-9) up to 477 patients, stationed at Ulithi with Okinawa and
Battle of Iwo Jima patients. ==Net laying==