Marine paratroopers started on the north shore of the larger islet, close to one end of the causeway. Facing them were Japanese service troops in front of one cave-riddled hill. Hiding in those caves were an ATG and a platoon of elite SNLF. Across the causeway was an SNLF HMG in caves in front of another steep hill, topped by a 75mm battery. All of the non-service troops were hidden.

The marines had great success assaulting the front line of Japanese service troops, although naval and air support were largely ineffective and soon withdrew. A platoon of paratroopers and engineers were landed behind the flank of the Japanese line and were able to assault uphill to take out the ATG. As the Marines finished off the service troops, they ran smack into the SNLF in their caves and took their first step losses. The Marines consolidated their position and awaited for the first wave of reinforcements.

Just before nightfall a company of Marines supported by 2 platoons of HMGs waded ashore at the far end of the causeway, on the smaller islet, on the only two open beaches there. Braving the fire of both the SNLF HMG and the hilltop artillery they pinned the SNLF down and took out the artillery in a daring assault up the steep hill. Japanese resistance was down to a half-strength HMG on 1 islet and a platoon of SNLF on the other islet as night fell. Both sides rested through the night to avoid unnecessary disruptions, and a pair of M5 tanks clanked up to the causeway to prepare for the renewed assault the next morning.

At first light on the 2nd day, both assaults kicked off again. Within 45 minutes both positions were taken.

In less than 24 hrs the Marines had eliminated all resistance on Gavutu-Tanambogo, at a loss of only 40 casualties and damage to one destroyer.

The Japanese lost too many units early on defending the ground in front of their caves. They should have filled the caves with troops instead, which would make them nearly impossible to root out. I had anticipated the Marines having a tougher time fighting in the open, but that was no problem. The caves were a much more difficult task, even when only lightly held.