The best memory card is first the one your camera officially supports. After compatibility, prioritize sustained write performance for your burst/video workload, reputable manufacture and enough separate cards that one failure does not hold the entire trip.
Do not buy on headline speed alone
Card labels can advertise maximum read speeds that matter more for file transfer than continuous shooting. Check your camera maker’s tested or recommended card specifications and the card’s sustained/video speed class where relevant.
Several cards or one enormous card?
Multiple cards spread failure risk and make it easier to rotate media after backups. Very small cards, however, create unnecessary swapping in bad weather. Choose a capacity that comfortably covers a shooting session.
Cards are not your only backup
When practical, copy photographs to a separate SSD or computer while retaining the original card until another verified copy exists. Remote Falklands locations do not have camera shops around the corner, so redundancy matters.
Choose the card specification your camera can use
A UHS-II V90 SD card can be valuable for high-bitrate video or deep bursts, but it adds little if the camera slot only supports slower standards. CFexpress Type A and Type B are physically different and not interchangeable. Check the camera manual, then buy reputable cards from trustworthy sellers; counterfeit storage is a bigger risk than choosing the second-fastest genuine model.
