Sea to Summit’s Spark are the lightest and most packable in the brand’s entire range. Designed to deliver versatile warmth on adventures where weight and pack size are at a premium, they feature a stripped-back and minimal design that’s been created to deliver on that brief. The Spark SPII is the second lightest in the line, promising to keep you warm down to temperatures of around 38°F / 4°C.
To maximize weight and packability, Sea to Summit have filled this bag with super-lofty 850+ fill power down. The result is a bag that barely weighs 500g and packs down to the size of a one-liter Nalgene bottle. To me, this makes it one of the lightest and most packable bags I've ever tested – if not lightest and most packable bag I’ve ever tested.
That status has come at the expense of quite a few sacrifices, however; the Spark SPII offers fewer features than many equivalent bags, while still costing a hefty $409 / £400 when bought directly from Sea to Summit. Naturally, then, this bag isn’t one for the weekend warriors. It’s for multi-day and for whom grams are more important than pounds (or dollars).
Is it worth this initial high investment, then? Or is it too minimal to keep you comfortable outdoors? To make the bag so small and light, Sea to Summit have had to make a few sacrifices. Firstly, there’s no neck baffle, which is something I certainly missed on colder nights. Instead, a singular drawcord pulls everything in, which still does a great job of keeping in t.