Sea to Summit Spark Pro
Summary
Price At Time Of Writing | $649.00
Our Overall Rating | 92 out of 100
Pros - Lightweight, incredibly warm, packed with smart features
Cons - Expensive and the lightweight fabric requires careful handling
Overall - A top-tier sleeping bag that delivers on performance, comfort and durability
Technical Specifications
Packed Size - N/A
Weight - 1lb 11oz
Fill - 950-fill Ultra-Dry Down
Our Analysis & Ratings
The Sea to Summit Spark Pro 15oF Sleeping Bag is a high-performance, ultralight sleeping bag designed for hikers who demand warmth without the bulk. Building on the success of its predecessor, this updated model introduces new features while maintaining the lightweight and compact design Sea to Summit is known for. With premium 950+ fill-power down, versatile ventilation options and a thoughtful baffle system, this bag is ideal for three-season use and even milder winter conditions. Whether you're a long-distance trekker or a weekend camper, the Spark Pro offers a fantastic balance of comfort, durability and packability that makes it a standout choice.
Comfort - One of the most impressive aspects of the Spark Pro is its comfort. The 950+ fill-power down provides excellent loft, giving you plenty of warmth without excessive weight. The ergonomic mummy shape keeps you snug, while the anatomical footbox gives plenty of space for larger feet. The cushy neck and head draught collars prevent cold air from sneaking in and the ability to unzip the footbox or fully open the bag into a quilt allows for temperature regulation. Side sleepers will appreciate the mixed baffle design, which prevents cold spots and keeps the down evenly distributed.
Construction - Sea to Summit has used top-tier materials in the Spark Pro’s construction. The 10D nylon shell is lightweight yet durable, though it requires careful handling to avoid damage. The non-PFC Ultra-Dry down treatment gives it warmth even in damp conditions, and though it’s not waterproof, it resists moisture better than untreated down. The full box baffles prevent down migration, maintaining consistent insulation. The Free-Flow Zip System is a standout feature, allowing multiple ventilation options, including converting the bag into a quilt. The zippers glide smoothly without snagging, a rarity in many sleeping bags.
Features - The Spark Pro is packed with clever features. The three-zipper system (shoulder, side and footbox) gives you unmatched versatility, letting you adjust ventilation or even walk around camp with the bag partially unzipped. The waterproof-breathable fabric in the hood and footbox resists condensation, a thoughtful touch for tent campers. It also comes with both a compression sack for packing and a larger storage sack to maintain loft when not in use. While some may find the extra zippers excessive, they add functionality for those who like to fine-tune their sleeping setup.
Size/Weight - Weighing just under 800 grams, the Spark Pro is impressively light for a 15oF bag. The regular size fits individuals up to 6.06ft, while the long version accommodates those up to 6.5ft. Despite its generous dimensions (24in shoulder width, 21in hip width), it compresses down to a compact 7 litres, making it easy to fit in a backpack. The balance between space and packability means you won’t feel cramped, yet it won’t take up unnecessary room in your pack.
Versatility - This bag also excels in versatility. The ability to fully unzip it into a quilt makes it suitable for warmer nights, while the 15oF rating ensures warmth in colder conditions. It can also be paired with the Sea to Summit women’s version for a double bag, though this might be more of a novelty for most. The multiple ventilation options mean it adapts well to varying temperatures, though in peak summer, a lighter bag might still be preferable.
Overall - The Sea to Summit Spark Pro 15oF Sleeping Bag is a premium option for hikers who are looking for a mix of warmth, weight and versatility. While it sits at the higher end of the price spectrum, the quality materials, innovative features and thoughtful design justify the cost. Honestly, it’s not just a sleeping bag, it’s a well-engineered system that adapts to different conditions, making it a reliable choice for year-round adventures. If you’re after a high-performance bag that doesn’t compromise on comfort or packability, the Spark Pro is hard to beat.
