Rough seas on 6 October and 7 October prevented a landing, but on 8 October the sea was finally calm enough for a landing to take place, and Admiral Lespès landed his 600
fusiliers-marins opposite the New Fort early in the morning. Captain Martin of
La Galissonnière, the officer originally scheduled to command the attack, was ill, and command of the attack was transferred at the last moment to
capitaine de frégate Boulineau of
Châteaurenault. The squadron was deployed in line ahead off the harbour entrance to support the attack, facing north. The line was headed by
Châteaurenault, followed by ''d'Estaing
, Tarn
, Triomphante
, Duguay-Trouin
and La Galissonnière
, with Vipère'' bringing up the rear. Many of the town's European residents, excited by the prospect of a battle, formed picnic parties and flocked to vantage points on the nearby hills to obtain a good view of events. They were confident that the French would win, and expected Tamsui to be in French hands by nightfall. Boulineau deployed his five companies into two lines, with a strong guard out to the left where the danger of a flanking attack by the Chinese was strongest. His first line consisted of the landing companies of
La Galissonnière and
Triomphante, each of 120 men, under the respective command of
lieutenants de vaisseau Fontaine and Dehorter. Dehorter's company held the right of the line. The second line, behind the first, consisted of the two mixed companies from the smaller ships, each of 130 men. The company from
Tarn and
Duguay-Trouin, under the command of
enseigne de vaisseau Deman, was on the right, behind Dehorter's company.
Bayard's landing company, 100 men strong, was posted on the left flank of the main body. The deployment, which was completed by 10:00 am was protected by naval gunfire from the French flotilla, which swept the ground between the beach and the forts. At 10 am, Boulineau led his small force forward at a smart pace over the sand dunes. Things immediately began to go wrong. The dunes had hidden the ground beyond from the sight of the French squadron. The French had been expecting to find an open terrain of rice paddies and small clumps of trees. Instead, they discovered that the approaches to the forts were thickly wooded. The battlefield was dotted with small cultivated fields surrounded by tall hedges and spiny plants. The ground was also broken by ditches, and covered with tall bushy trees. This broken terrain provided perfect cover for the Chinese, and made control by the French commanders almost impossible. The companies and sections lost sight of one another as soon as they entered the scrub. They also began to drift off the line of advance prescribed by Admiral Lespès. Boulineau realised that there was nothing he could do to regain control, and decided he would have to rely on the initiative of his company commanders. The New Fort was still visible in the distance, so the four companies of his main body could at least see the direction in which they were supposed to be heading. Meanwhile, the Chinese had begun to put pressure on the French left. Despite the supporting fire provided by the French ships, Zhang Gaoyuan's troops were able to force back the French flankguard from
Bayard, pushing it back on the French main body.
Bayard's sailors were able to link up with Deman's company, but the French landing force was now deployed in a single line around long. It no longer had any reserves. The firefight extended along the entire French front. The Chinese and French were separated by a distance of about . The situation called for regular, controlled volleys by the French, but the excited sailors were firing individually into the bushes, as fast as they could. Boulineau realised that they were simply wasting their ammunition. He repeatedly yelled orders to his men to cease fire, but only a small part of his command could hear him. No bugle signals could be sent, as Boulineau's bugler had been shot dead shortly after the start of the action. The French line continued to waste its ammunition on an elusive target.
Lieutenant de vaisseau Augustin Boué de Lapeyrère of
Vipère realised the potential danger of a Chinese counter-attack, and was given permission by Lespès to move his small gunboat to a position close inshore to cover the French withdrawal. From there it fired shells to keep the Chinese at a distance. At half past midday the first boats put out from the shore and steered towards the French ships. By 1:10 pm, they had all left the beach.
Vipère followed them slowly, firing at increasingly long range at the Chinese troops on the shore. At 1:30 pm the boats reached the ships. The sea was now very rough, and the wounded cried out in pain as their comrades helped them up the ladders onto the ships' decks. == Aftermath ==