Which memory card to choose for uninterrupted 4K or 8K underwater video recording?
Recording underwater video in 4K or 8K requires choosing a memory card based on its guaranteed sustained write speed rather than peak read speed. Class V30 cards are perfect for action cameras, whereas mirrorless cameras recording All-Intra require V60 or V90 cards to prevent unexpected buffer cutoffs during a dive.
Identify in 3 clicks the ideal SD or microSD card based on your camera body, write speed requirements, and marine durability needs.
Action cam, rugged compact or professional mirrorless body
Standard 4K, high-bitrate 4K/6K All-Intra or cinema 8K
Solid resin waterproof build, proven reliability or ultra-high capacity
Action cameras like GoPro, DJI Action, or Insta360 use compressed bitrates between 80 and 120 Mbps (10 to 15 MB/s). A V30 card guarantees 30 MB/s, which provides a 100% safety margin. Buying an expensive V90 card for an action camera provides zero image benefit, because the camera bus is limited to UHS-I speeds.
Filters for guaranteed sustained write speed, UHS-I / UHS-II interfaces, and head-to-head comparison.
Official manufacturer specifications, minimum sustained video classes, and seawater resistance.
| Model | Brand | Format & Bus | Video Class | Guaranteed Write | Peak Write / Read | Marine Durability | Official Site |
|---|---|---|---|---|---|---|---|
Extreme PRO microSDXC UHS-I 32 Go à 1 To | SanDisk | microSDXC (UHS-I) | V30 | ≥ 30 Mo/s | 140 / 200 Mo/s | Étanche IPX7, antichoc, rayons X, températures -25°C à 85°C | Link |
PRO Ultimate microSDXC 128 Go à 512 Go | Samsung | microSDXC (UHS-I) | V30 | ≥ 30 Mo/s | 130 / 200 Mo/s | Protection 6-Proof : eau de mer jusqu'à 72h, chutes 5m, magnétisme 15 000 gauss | Link |
 Canvas Go! Plus SD 64 Go à 1 To | Kingston | SDXC (UHS-I) | V30 | ≥ 30 Mo/s | 160 / 200 Mo/s | Étanche IPX7, résistant aux vibrations et aux rayons X d'aéroports | Link |
 Extreme PRO SDXC UHS-II V60 64 Go à 2 To | SanDisk | SDXC (UHS-II) | V60 | ≥ 60 Mo/s | 250 / 300 Mo/s | Blindage thermique, résistance aux embruns salés et aux chocs de pont de bateau | Link |
 SDXC UHS-II V60 Gold 64 Go à 512 Go | ProGrade Digital | SDXC (UHS-II) | V60 | ≥ 60 Mo/s | 130 / 250 Mo/s | Boîtier scellé avec fonction Refresh Pro pour surveiller la santé des puces mémoire | Link |
 Extreme PRO SD UHS-II V90 64 Go à 512 Go | SanDisk | SDXC (UHS-II) | V90 | ≥ 90 Mo/s | 300 / 300 Mo/s | Résistant aux conditions extrêmes de plongée, rayons X et humidité tropicale | Link |
 Professional 2000x GOLD SDXC V90 64 Go à 512 Go | Lexar | SDXC (UHS-II) | V90 | ≥ 90 Mo/s | 260 / 300 Mo/s | Résistant à l'eau douce et salée, aux températures polaires et tropicales (-25°C/85°C) | Link |
 AV PRO SD V90 MK2 64 Go à 512 Go | Angelbird | SDXC (UHS-II) | V90 | ≥ 260 Mo/s | 280 / 300 Mo/s | Coque sans encoche Write-Protect mécanique, insensible à l'usure et aux chocs | Link |
 SF-G TOUGH SDXC V90 32 Go à 256 Go | Sony | SDXC (UHS-II) | V90 | ≥ 90 Mo/s | 299 / 300 Mo/s | Norme IP68 étanche 72h à 5m d'eau, 18x plus résistante à la torsion que le standard SD | Link |
 Atlas Ultra SDXC V90 64 Go à 512 Go | OWC | SDXC (UHS-II) | V90 | ≥ 90 Mo/s | 295 / 310 Mo/s | Tolérance thermique certifiée, blindage contre les champs magnétiques et les chocs | Link |
 NX-F2PRO SDXC V90 64 Go à 256 Go | Nextorage | SDXC (UHS-II) | V90 | ≥ 90 Mo/s | 299 / 300 Mo/s | Résistant à l'eau douce et salée IPX7, protection statique et rayons X | Link |
 EliteX-PRO90 SDXC V90 64 Go à 256 Go | PNY | SDXC (UHS-II) | V90 | ≥ 90 Mo/s | 280 / 300 Mo/s | Résistant aux températures extrêmes (-25°C à 85°C) et aux chutes accidentelles | Link |
 EXCERIA PRO G2 SDXC V90 64 Go à 512 Go | Kioxia | SDXC (UHS-II) | V90 | ≥ 90 Mo/s | 300 / 310 Mo/s | Protection ESD, fusible de sécurité intégré, étanchéité IPX7 | Link |
 EXCERIA PRO G2 SDXC V60 64 Go à 512 Go | Kioxia | SDXC (UHS-II) | V60 | ≥ 60 Mo/s | 250 / 300 Mo/s | Résistant aux embruns salins, aux rayons X et aux chocs mécaniques | Link |
PRO+ microSDXC UHS-I V30 128 Go à 2 To | TeamGroup | microSDXC (UHS-I) | V30 | ≥ 30 Mo/s | 110 / 160 Mo/s | Étanche, antipoussière, résistant aux rayons X et aux températures extrêmes | Link |
A V30 UHS-I microSDXC card such as the SanDisk Extreme PRO or Samsung PRO Ultimate is fully sufficient. It guarantees 30 MB/s sustained write (240 Mbps), well above the 120 Mbps peak bitrates of modern 4K or 5.3K action cameras.
If the card drops below the required continuous write speed, the internal camera buffer overflows and recording cuts off after a few seconds. Underwater, opening the housing to swap cards is impossible.
Yes, always format your card inside the camera body before sealing the underwater housing. Formatting in-camera restores optimal file allocation block sizes.
Sony TOUGH cards are molded in a solid single-piece resin body without fragile connector ribs or mechanical write-protection switches. They offer 18x higher bend resistance and IP68 waterproof ratings.
Card manufacturers highlight peak read speeds (often 200 to 300 MB/s) on retail packages. When shooting underwater video, only the sustained continuous write speed guaranteed by the V30, V60, or V90 rating matters.
It is strongly discouraged for high-bitrate video. The additional contact pins in the adapter introduce electrical resistance and risk dropped frames during sustained RAW bursts or All-Intra video capture.