The Sea to Summit Big River 50L in the Picante colourway fully embraces a minimalist design philosophy. The result is an impressively low weight of just 760 g (26.8 oz) for a 50-litre waterproof backpack. It’s light enough to pack inside a travel bag “just in case”—which is exactly what we did during the Marathon des Sables, where it protected all of our gear from the race’s notorious sandstorms. That was admittedly an unconventional use, as the Big River is primarily designed for canyoning, kayaking and any adventure where your equipment needs reliable protection from water, mud or dust.
One point deserves particular attention: at this weight, you shouldn’t expect the carrying comfort of a traditional trekking backpack. To keep the weight to a minimum, the back panel has no structural padding. As a result, careful packing is essential. Soft items should be positioned against your back, while hard or bulky equipment should be kept away from the spine to ensure comfortable carrying.
The shoulder straps, however, are well proportioned and surprisingly comfortable despite using relatively firm foam that should prove highly durable over time. The hip belt and adjustable sternum strap are equally effective, offering secure adjustment with webbing that slides smoothly and is easy to tighten.
The minimalist approach is also apparent in the carrying handles. When the shoulder straps aren’t accessible, the bag can be awkward to grab. Each side features a daisy chain that can also be used to reposition the roll-top compression straps, but it isn’t particularly easy to grip. On the plus side, its low profile makes it far less likely to snag on branches or other obstacles. A thin cord at the top of the bag provides an alternative carrying point. It works well for short lifts, although when the pack is heavily loaded, the narrow cord quickly becomes uncomfortable in the hand. It’s a lightweight solution that some users may even choose to remove.
Waterproofing is achieved through the classic roll-top closure. Rolling the top at least three times before clipping the side buckles creates a secure, watertight seal. One particularly welcome feature is the bright interior fabric, which makes it much easier to locate your gear inside the bag, even in low-light conditions.
The Sea to Summit Big River 50L is both lightweight and highly versatile. At just 760 g, it provides dependable protection for your equipment in almost any environment where water, sand or mud are a concern. Its minimalist construction inevitably sacrifices back support in favour of weight savings, but for users who prioritise low weight and waterproof performance, it is an excellent choice. A very capable waterproof backpack.
We used this equipment over a long period of time
These are our thoughts after intensive use:
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