Sea to Summit Trek Down -9
Summary
Price At Time Of Writing | $599.99
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 - 1.44kg
Fill - 650-Fill Duck Down
Our Analysis & Ratings
The Sea to Summit Trek Down Sleeping Bag is perfect for campers and travelers who want a mix of warmth, comfort and flexibility. It uses 650+ fill power duck down (ethically sourced) and has a semi-rectangular shape, giving you more room than a snug mummy bag without sacrificing warmth. The 2024 model now has a full Free-Flow zipper system for better airflow. While it’s not the lightest option for hardcore backpackers, it’s great for car camping, road trips and shorter hikes.
Comfort - The semi-rectangular design gives side sleepers plenty of space to move and you can even stretch out or unzip the footbox if you like. The down is soft and cozy, though the inner fabric can stick to bare skin, so a liner might help if you sleep in minimal clothing. The hood is nicely padded and works well with an Aeros Pillow for extra neck support.
Construction - Sea to Summit’s build quality is great, with a tough 20D polyester shell and strong stitching. That said, some down can escape near the zippers over time. The Free-Flow zipper is a cool feature, as it lets you open the bag from the top, sides, or bottom, but it’s a bit more complicated than a standard two-way zipper. The down is treated to resist moisture, but the bag can stay damp if you sweat inside.
Features - The best thing about the Trek Down is how adaptable it is. The triple zipper lets you vent the bag or open it fully like a blanket. You can even zip two bags together for couples. The included stuff sack and storage bag are handy, though the outer fabric could be tougher for rough use. The -9°C rating is accurate for most, but if you run cold, you might need extra layers near freezing.
Size/Weight - At 1.44kg and packing down to 10.6L, this isn’t the lightest or smallest bag, but it’s a fair trade-off for the warmth. Tall folks (up to 6’1”) should get the long version, but the regular size fits most people fine. If you’re used to ultralight gear, it might feel bulky, but it’s manageable for car camping or short backpacking trips.
Versatility - This bag works well in three seasons; use it fully unzipped in summer or snug in fall. Zipping two together is great for sharing. The semi-rectangular shape is comfy but not as warm as a tight mummy bag in deep cold, so winter backpackers might need something more weather-specific.
Overall - The Trek Down is a great all-around choice if you prioritise comfort and flexibility over ultralight packing. It’s roomy, warm and the zipper system adds useful options. While not flawless, the quality and versatility make it worth the price for casual backpackers, car campers and travelers.
