Sea to Summit Trek Down 15
Summary
Price At Time Of Writing | $399.00
Our Overall Rating | 83 out of 100
Pros - Spacious, comfortable, adaptable
Cons - Not ultralight or compact, minor down leakage, slightly fussy zipper system
Overall - Great sleeping bag for car campers and moderate backpackers
Technical Specifications
Packed Size - N/A
Weight - 3lb 2.7oz
Fill - 650-Fill Duck Down
Our Analysis & Ratings
The Sea to Summit Trek Down Sleeping Bag is designed for campers and travellers who want a balance between warmth, comfort and versatility. With a 650+ fill power RDS-certified duck down insulation and a semi-rectangular cut, it offers a roomier alternative to traditional mummy bags while maintaining thermal efficiency. The 2024 update introduces the full Free-Flow zipper system, allowing for better ventilation and adaptability. While it’s not the most compact option for ultralight backpacking, it’s a good choice for car camping, overlanding, and moderate backpacking trips.
Comfort - Comfort is where the Trek Down truly stands out. The semi-rectangular shape provides ample space for side sleepers and those who prefer a more spacious sleeping experience. It’s even roomy enough to stretch out or sleep with your feet unzipped. The down filling is plush and warm, though the inner fabric can feel slightly clingy against bare skin, meaning you may want to use a liner if you prefer sleeping in minimal clothing. The hood is well-padded and can be paired with an Aeros Pillow for added neck support.
Construction - Sea to Summit’s build quality is generally excellent, with durable 20D polyester shell fabric and reinforced stitching. There are, however, some minor issues with down leakage near the zippers, which could be a concern over time. The Free-Flow zipper system is innovative, allowing the bag to open from the top, sides and bottom, but it’s also a bit complicated compared to traditional dual-slider designs. The non-PFAS Ultra-Dry Down treatment and DWR finish help resist moisture, though we sometimes notice lingering dampness after sweating inside the bag.
Features - The Trek Down’s standout feature is its adaptability. The triple-zip system lets you vent the bag as needed or fully open it into a quilt-like blanket. Two bags can also be zipped together to create a double sleeping bag, which is a great perk for couples. The included compression sack and storage bag are well-received, though we notice the outer fabric could be more abrasion-resistant for rugged use. The temperature rating (15°F) is accurate for most, though cold sleepers may want to layer up in near-freezing conditions.
Size/Weight - Weighing 3lbs 2.7oz and compressing to 10.6L, the Trek Down isn’t the lightest or most packable option, but it strikes a reasonable balance for its warmth category. Tall people (up to 6’1”) will be better with the longer version, though the standard size should be enough for average heights. Those transitioning from ultralight gear might find it bulky, but for car camping or shorter backpacking trips, the weight is manageable.
Versatility - This bag does great in terms of adaptability. It works well across three seasons, from summer camping (used fully unzipped) to chilly fall nights. The ability to pair it with another Trek Down bag adds functionality for shared sleeping spaces. The semi-rectangular design, however, while comfortable, isn’t as thermally efficient as a true mummy bag in extreme cold, so winter backpackers may need a more specialized option.
Overall - The Sea to Summit Trek Down Sleeping Bag is a well-rounded choice for campers who are looking for something comfortable and flexible over ultralight minimalism. Its roomy cut, reliable warmth and innovative zipper system make it great for casual backpackers, car campers and travel use. While not perfect, the overall quality and versatility justify the investment.
