[2] Her commander, Captain Jorge Gopcevich-Canevari claims that his ship had evaded the vigilance of a British frigate in the same area while carrying out a similar mission on 14 May.

[2] Corvette Lieutenant Oscar Vázquez, Gopcevich's second-in-command, later reported that while Brilliant was approaching them from the south, Yarmouth sailed ahead to Choiseul Sound, blocking the passage from the north.

[6] HMS Yarmouth began to fire her 4.5-inch (114 mm) guns on the Argentine vessel, forcing her to manoeuvre in order to avoid the incoming rounds.

When the distance fell to four nautical miles (7.4 km), Gopcevich decided that the only way to deceive the British radar was to beach Monsunen on Seal Cove, a large inlet nearby.

[6] The British warships eventually called off a second SBS assault on the grounded Argentine vessel as it was unclear whether troops on board "could have stay behind in ambush".

[8] The British frigates gave up their chase and withdrew from the area before sunrise; Yarmouth, with the SBS detachment aboard, headed to San Carlos waters, while Brilliant joined the carrier group for refuelling.