The pack we
couldn't buy.
Twenty-six litres, fully welded, fully submersible. Four years with Fourth Element to build the waterproof haul pack that didn't exist — and now refuses to fail.
- capacity
- 26 L
- rating
- IPX 7
- weight
- 1160 g
- shell
- 600D
EP01
26 L · IPX7
An expedition needed a backpack that could survive full submersion. Nothing on the market held up. So we stopped looking, and spent four years building the one we wanted.
01 — Shell
A shell with
no way in.
Radio-frequency welded seams replace every stitch a needle would have left behind — no holes, no wicking, no slow leak you only notice once your kit is wet. The 600D shell sheds water on contact and keeps the inside dry through full immersion.
- seams
- RF-welded
- shell
- 600D
- rating
- IPX7
Drop it in.
Pull it out dry.
No roll-top — we never trusted them. We sealed every way water could get in.
-
01
100% submersible & waterproof
Every bag seam is welded — the whole body is fully submersible, not just splash-proof.
-
02
YKK AQUASEAL®
A lightweight, top-of-the-line water- and air-tight zipper — the same kind used on commercial drysuits.
-
03
APOLLO® air-escape valve
The EP01 is so waterproof it's airtight — just like a drysuit. The valve lets trapped air out so you can pack it down.
Carried into more than 30 countries. Returned from all of them.
03 — Cube system
Packs the way
you think.
The interior locks to the CB cube system — colour-keyed packing cubes in two sizes, medium and small, that clip in and out so the pack reconfigures for a dive day, an overnight or a flight without you repacking from scratch. Nothing rattles, nothing shifts.
- sizes
- medium · small
- mount
- clip-lock
- material
- water-repellent light ripstop nylon
Weights & materials
Every component, named and weighed. Nothing on the pack that hasn't earned its place.
Built with
Fourth Element.
We partnered with the dive-kit specialists at Fourth Element and spent four years prototyping, drowning and rebuilding the pack until nothing failed. Every revision went back into the field — not a lab — before it earned the next one.
- design & test
- 4 yr
- partner
- Fourth Element
- environments
- 9
Fourth Element
Order the EP01
One pack, one finish — built to order in small runs. We'll get it to you.
EP01 Field Pack
Twenty-six litres, fully welded, fully submersible. One finish — matte welded shell, blacked-out hardware.
Field notes
Test reports, new releases, and the occasional failure we learned from.