US Marine Corps - The Black Vault

WATCHTOWER 275
The day previous, 16 July, when Vice Admiral Ghormley issued his
Operation Plan for WATCHTOWER, the information in regard to the
landing field near Lunga Point on Guadalcanal in the Intelligence Annex
read as follows:
Troops observed burning grass plains behind Lunga, Tenaru, and Kukoom on
July 14, no actual work on runways was observed.
The plan further confirmed the lack of definite information on 16 July 1942
by ordering that:
On Dog Day capture and occupy Tulagi and adjacent positions, including
an adjoining portion of Guadalcanal suitable for the construction of landing
fields. Initiate construction of landing fields without delay.
It was not until 25 July, as Rear Admiral Turner was worrying about the
landings soon to be rehearsed in the Fijis, that CINCSWPAC reported
large airdrome nearing completion eight miles east of TENARU.
The quite obvious error as to where the airdrome actually was located was
corrected in due time to locate it two miles south of Lungs Point and on the
east side of the Lunga River.115
The high powered and presumably all-seeing Joint Intelligence Committee
(JIC) in Washington had no better information on this all important subject.
The JIC Daily Summary of 10 July 1942 stated:
G?~adalcat?aI IsLmd. There are indications of construction on an airfield.
Ten days later the JIC noted:
Gt~adalcatzal. Runway completed on 20 July 1942
It might be noted as a lasting memorial to Rear Admiral Turner’s mistaken
desire to keep the Office of Naval Intelligence and all related Army
intelligence activities ignorant of impending naval operations, that in the
28-day period between 10 July and 7 August, when WATCHTOWER was
really being launched, there were only six mentions of Guadalcanal Island
in the JIC Summaries. The only other one of particular moment was on
26 July when it was noted:
An enemy airdrome appears to be nearing completion on Guadalcanal Island
and another is under construction .116
The failure of both Naval and Army Air Force air reconnaissance to give
to COMPHIBFORSOPAC a clear day-by-day report of progress on the
‘=CM-IN-8926 7/26/42; CM-IN-9973 7/29/42.
‘wJIC Intelligence Summaries, 16 Jun. 1942 to 8 Aug. 1942,