We attempted to use vesicle sizes in lavas erupted near sea-level from the ~2.9 Ga Pongola Supergroup from Mahlangatsha and Mooihoek, eSwatini (formerly Swaziland) and the White Mfolozi River gorge of KwaZulu-Natal, South Africa to provide further Archean paleobarometric data. However, reliable results were unobtainable due to small and scarce amygdales, irregular vesicle morphologies and metamorphic mineralogical homogenization preventing the use of X-ray Computed Tomography for accurate vesicle size determination. Researchers attempting paleobarometric analysis using lava vesicle sizes should henceforth avoid these areas of the Pongola Supergroup and instead look at other subaerially emplaced lava flows. With this being only the second time this method has been used on Precambrian rocks, we provide a list of guidelines informed by this study to aid future attempts at vesicular paleobarometry.