The Unauthorized History of the Pacific War

Operation WATCHTOWER

Episode Summary

This week Seth and Bill examine the preparations for the Operation WATCHTOWER-the invasion of Guadalcanal and Tulagi. The team dives deep into the planning and preparation of the first American ground offensive of the Pacific War.

Episode Notes

A Rush to Action the beginnings of a “plan”

• On July 3, just after WATCHTOWER is approved (but not by the Joint Chiefs) King flies to Frisco to brief Nimitz
• Richmond Kelly Turner was told that 3 CVs would support the operation (CV3, CV6 and CV7)
• The name Guadalcanal had not yet been added to the operation list as a target as of July 3
• On June 27, to follow King’s initial order to prepare to seize Tulagi, Nimitz ordered Tulagi to be captured and the “seizure of an airfield” adjacent to Tulagi as well…but specified no exact location.
• On July 5 it was reported that the Japanese had landed airfield construction troops and equipment on Guadalcanal, only then was Guadalcanal added as a target.
• Also on July 5, the new target received its code name…Cactus

• Why Guadalcanal and Tulagi?
• Once the Japanese established a seaplane base at Tulagi in May, that base could disrupt the sealanes between the US, HI, Fiji, Samoa and most importantly, Australia
• It was feared that the establishment of a larger airfield on neighboring islands (Canal) would further inhibit shipping and cede control of those waterways to the Japanese.

Questionable from the start:

• Admiral Robert L Ghormley had just recently assumed duties as COMSOPAC and as such, WATCHTOWER would fall under his purview.
• Those under his command would be: 1st Mar Div, 3 CV groups under the command of Vice ADM Frank Jack Fletcher, as well as South Pacific Amphib Forces under Rear Adm Richmond Kelly Turner.
• All of these forces would be (theoretically) supported by land-based air under RADM McCain, Allied Air Forces SWPAC under MacArthur and GEN Kenney
• Upon receiving orders to seize “Tulagi and adjacent positions” Ghormley immediately showed what would be his calling card…pessimism.

• Ghormley immediately concluded that he and his people were nowhere near ready to tackle such an operation
• In a way, he was correct.  He had exactly 1 Marine on his staff that had any experience in amphibious operations, and he had very, very little.
• Comms to and from Ghormley’s staff and HQ were hours and sometimes DAYS late in arriving or being sent
• Intel on the area was virtually NILL.
• Charts of the GCanal and Tulagi area were woefully outdated.
• Any actual intel, of which there was essentially none, came from coastwatchers or aerial photos
• Maps of Guadalcanal were from 1910 charts that were “corrected” by aerial photography

• Air Power, or lack thereof, was a major concern before the operation even began
• There were no land bases close to the target area from which air support missions could be flown and the aircraft on hand were too old and too few in reality
• ADM McCain’s considerable number of aircraft on hand (282) was deceiving
• Most of the aircraft were obsolete, and even if they weren’t, such as the case with the F4Fs, P39s and P400s under his command, they did not have the range to support an operation over 590 and 715 miles from the only US bases in the area Espirtu Santo and Efate, respectively that had decently sized airfields.

• On July 8, Ghormley flew to Melbourne and spoke with MacArthur.  The problems outlined by the GEN and the ADM were:
• Gaining and maintaining air superiority over the islands, the beaches and assault ships
• In a surprising moment of clarity and truthfulness, MacArthur admitted that his air forces probably could not interdict incoming Japanese air raids from Rabaul
• The protection of the islands and beaches and the like would fall upon Nimitz’s CVs
• This could/would be problematic in that the CVs could and would be pulled out due to any threat that may arise, therefore leaving the transport group and the beachhead itself totally without air support

• The basics of any amphibious operation were already less than stellar before the operation ever launched.
• The US would have air cover only as long as the CVs were present
• And that depended on the situation which would be very, very fluid

• There would be no US land-based air cover until a unit, or units, could be deployed to Guadalcanal, and who knew how long that would take

• The allied naval force would more than likely have to fight off a Japanese counterattack, probably at night, when the allied forces had little to no night fighting experience

• The assault troops would have to be properly trained for not only an opposed amphibious landing, but a sustained occupation and defense with the prospect of little to no reinforcement immediately coming

• Intelligence on enemy troops ashore, their number and strength was severely lacking.

• Intel on enemy air power as well as naval units was also severely lacking

• For all intents and purposes, the US and her allies were going into the operation blind and with one, or damn near both, hands tied behind their back.

The Old Breed

• Assault troops would be the 1st Marine Division
• Under the command of a brand-new MAJ GEN, Alexander Archer Vandegrift.
• 57 Years Old, 34 years a Marine
• Wickedly smart and intuitive, could grasp a situation and its necessities within seconds and make the right call
• Excellent judge of character and men, much like Nimitz, he was a quiet leader who always seemed to be optimistic about everything.

• 1st Mar Div was a brand-new unit, just recently formed, the division would be hamstrung by only having 2 of its 3 infantry regiments available for the initial assault
• 1st and 5th Marines.  The 7th Marines were garrisoning Samoa at the time.

• On May 1, five days after the 7th sailed for Samoa, the 1st Mar Div was ordered to New Zealand to prepare to be the Landing Force of the SoPac Amphib Force
• Vandegrift’s regiments were NOT ready for action.
• 5th Marines had been stripped of cadre and experienced men during the constitution of the 1st Raider BTLN.
• 1st Marines were even less prepared although they had strong BTLN level leadership
• The bright spot for 1st Mar Div was the divisional artillery, the 11th Marines.
• Highly proficient, the 11th Marines fielded a wide variety of the newest artillery available…they would be needed…many many times over

• The vast majority of Marines assigned to the 1st Mar Div were young, very young.
• Average age was 19 years old
• Post Pearl Harbor enlistees who believed in the Corps’ motto of First to Fight

• The division got the name Old Breed due to its cadre, which admittedly was small, but legendary
• Some WWI combat vets, recruiters, veterans of the banana wars, China Marines

• The division arrived in New Zealand on June 14
• On June 26, Vandegrift was told by Ghormley that his division would assault Tulagi and Guadalcanal on August 1

• Due to a longshoreman’s strike in Wellington, the 1st Mar Div had to combat load their ships themselves, a task for which they were not skilled, nor had the proper time to complete.
• This would be HUGE later on…

The Plan

• D-Day was set for August 1, for a variety of reasons D-Day would actually be August 7
• 1st and 5th Marines would assault Guadalcanal, while at the same time 4 rifle battalions, most Raiders, would assault and capture Tulagi
• D-Day objective for Guadalcanal was the airfield and the “grassy knoll” (Mt Austen)
• The Navy would supply:
• Combat Group:
• 3 CVs
• 1 fast BB (BB55)
• 9 CAs
• 2 AA CLs
• 31 DDs
• 2 Royal Australian CAs and 1 CL
• Amphib Group
• 13 transports
• 6 cargo ships
• 4 APDs
• 5 Oilers

The Japanese

• After the defeat at Midway, the Japanese realized that strengthening their outer ring of defenses was now imperative.
• On May 28, several Japanese landed on Guadalcanal to inspect the area
• Shortly after that, and after Midway, the Japanese authorized Operation SN, which was to strengthen their outer perimeter of their advance by constructing airfields at key strategic points in Papua, the Louisades and the Solomons.

• On June 13, the Naval General Staff selected Guadalcanal as an air base
• On July 6, the first Japanese construction forces landed, and on the 20th, work began on the airfield

• The Japanese did not believe that the Allies could or would mount an offensive until 1943 at the earliest
• Japanese ADM Mikawa believed that the US would assault and occupy Guadalcanal before the Japanese could complete the airfield.
• His ideas were scoffed at

• Focus for the IJA and IJN lay on Port Moresby and the assault over the Owen Stanley Mountains, not the Canal
• Focus shifted back to Guadalcanal on July 31, when for a week, B-17s bombed Guadalcanal almost daily suggesting a pre-invasion bombardment

• Japanese did not believe, as a group, that Guadalcanal would be attacked.
• Their defensive forces were meager:
• Only 3457 men were on both Tulagi and Guadalcanal
• 2571 were on Guadalcanal
• They were almost as unprepared as was the US in terms of a ground attack or defense
• The IJN was significantly more prepared however
• Because of Rabaul and its distance from Canal, the Japanese could and would attack the island and the ships offshore with long range medium bombers (Bettys) and Zero fighters

The kickoff

• On July 26, the fleet rendezvoused off Koro in the Fijis
• That afternoon McCain, Turner, Crutchley and Vandegrift all met aboard CV3
• Conspicuously absent was the overall CO, Ghormley who elected to not go to the meeting and therefore was deprived of any real operational plans of the overall operation until SEPTEMBER
• Fletcher led the meeting
• Vandegrift stated later that Fletcher seemed nervous, and was also “disconcertingly uninformed” about the landing plans

• Fletcher stated to all his subordinates that he felt that the plan would fail and blamed Turner who Fletcher said had no combat experience and as a result would hinder the operation to the extent of failure.

• Fletcher asked Turner how long it would take to unload the transports to which he replied 5 days.  Fletcher abruptly stated that he would pull his CVs after 2 days. He later said 3 days.

• After being given the context of the “meeting” by his aide Daniel Callahan, Ghormley essentially ignored the warnings that Fletcher seemed “scared” and proposed a faulty air support op from Efate that would never work and never was tried.

• Regardless of the inauspicious start, plans, intel, etc the operation was underway.

CLOSER: Official USMC history states regarding the beginnings of WATCHTOWER, “Seldom has an operation been begun under more disadvantageous circumstances.”