Borey was under pressure since his ships could only cross the bar at high tide and chose to follow his orders from Rear Admiral Edgar Humann in Saigon rather than Pavie's counsel.

Chulachomklao Fort had just been modernized with seven 6-inch Armstrong Whitworth disappearing guns and was under the command of Andreas du Plessis de Richelieu, a Danish naval officer granted the noble title of Phraya Chonlayutyothin.

Contemporary French accounts suggest that five gunboats were anchored just beyond the sunken vessels, almost the entire Siamese fleet.

Herbert Warington Smyth who visited Paknam that day disputes this, reporting that only the Siamese gunboats Makut Ratchakuman and Coronation were present, together with "two very old-fashioned gun flats with a big gun each, and the training barque,[a] lying farther up river, armed with six brass carronades for saluting purposes".

At least two shots from fortress hit the Inconstant, but more effective action was prevented by a lack of training at the fort.

By Warington-Smyth's account "these officers were running breathlessly to their guns in turn up and down half-finished steps and gun-platforms, avoiding pitfalls as best they might, and communicating their orders in languages which none of the astonished gunners understood."

The Jean Baptiste Say was hit several times by cannon fire and the captain was forced to ground her on Laem Lamphu Rai.

By this time night had fallen and after "five minutes' desultory firing of the wildest kind" the gunboats passed unhindered.

[1]: 263–265 The following morning, Jean Baptiste Say's crew was still aboard their grounded vessel so the Siamese sent a boat and captured the steamer.

[1]: 267–268  A day later, the French gunboat Forfait arrived at Paknam and sent a boatload of sailors to recapture the mail steamer, but when they boarded the Siamese defenders repelled their attack.

His ships' guns were targeted on the royal palace to put pressure on the Siamese to resolve multiple territorial disputes that had arisen with France.