Japanese reaction to the Guadalcanal-Tulagi invasion was swift, if not initially very effective. At Rabaul, the principal Japanese base in the area, the local fleet commander, Vice Admiral Gunichi Mikawa, pulled together some ground troops, put them in six transports and ordered them off toward Guadalcanal, about six hundred miles to the southeastward. However, during the night of 8 August one of the transports had the ill-fortune to pass near the old U.S. submarine S-38, which sank her with over three hundred men. This forced the cancellation of this first of what would be many Japanese efforts to reinforce their embattled troops on Guadalcanal.
Meanwhile, Japanese planes from Rabaul were sent off to attack the invaders, or preferably their supporting aircraft carriers. In the early afternoon of 7 August, some 27 twin-engine bombers (of a type soon to be nicknamed "Betty") and 18 deadly "Zero" fighters, not having found the carriers, arrived over the invasion fleet. Making a high-level bombing attack, they achieved no hits and lost five bombers and two fighters in actions with U.S. carrier planes (of which the "Zeros" shot down several F4F-4 "Wildcat" fighters and one SBD scout bomber). A few hours later nine single-engine Japanese dive bombers (type "Val") appeared and scored a non-fatal hit on the destroyer Mugford. All of these attackers were lost, either shot down or ditched on the way home.
The Japanese tried again the next day, this time with 27 "Betty" bombers fitted with aerial torpedos and an escort of 15 "Zeros". Once more, they failed to locate the U.S. aircraft carriers, but made a daring low-level torpedo attack on the Vice Admiral Turner's amphibious force. Turner skillfully maneuvered his ships in the sound between Guadalcanal and Tulagi, throwing off the enemy's aim. Only one torpedo scored, hitting destroyer Jarvis in the bow. The transport George F. Elliot was struck amidships by a crashing bomber and was set afire. Japanese losses were very heavy, about seventeen bombers and two fighters, the great majority to the ship's anti-aircraft guns.
The damage done by these Japanese air attacks only inconvenienced the invasion force, slowing supply off-loading by a few hours and taking three ships out of the fight. George F. Elliot was a total loss, her fires burned out of control and she had to be scuttled. Jarvis and Mugford were both able to steam away to seek repairs, but the former, sailing independently, was found by enemy planes on the 9th of August and sunk with no survivors.
