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Reviews > Sleep Gear > Sleeping Bags > Therm-a-Rest Navis sleeping bag > Owner Review by Ray Estrella

Therm-a-Rest Navis Sleeping Bag
By Raymond Estrella

December 09, 2013


NAME: Raymond Estrella
EMAIL: rayestrellaAThotmailDOTcom
AGE: 53
LOCATION: North Western Minnesota, USA
HEIGHT: 6' 3" (1.91 m)
WEIGHT: 213 lb (96.60 kg)

I've been backpacking for over 30 years, all over California, Minnesota, and many western states. I hike year-round in all weather, and average 500+ miles (800+ km) per year. I make a point of using lightweight gear, and smaller volume packs. Doubting I can ever be truly ultralight, I try to be as light as I can yet still be comfortable. I start early and hike hard so as to enjoy the afternoons exploring/chilling. I usually take a freestanding tent and enjoy hot evening meals. If not hiking solo I am usually with my brother-in-law Dave or my twin children.

The Product

Manufacturer: Cascade Designs Inc. Navis
Web site:
Product: Navis Sleeping Bag
MSRP: US $249.95
Size: Regular (one size)
Year manufactured/received: 2013
Suggested temperature range: 25 to 45 F (-4 to 7 C)
Weight listed: 21 oz (610 g)
Actual weight: 20.4 oz (579 g)
Stuff sack weight: 0.85 oz (24 g)
Color: Orange
Amount of fill: 8 oz (235 g) of 750+ fill power goose down
Loft observed at quilted area: up to 1.5 in (3.8 cm) between stitching
Loft observed at baffled area: up to 2 in (5 cm) between baffles
Packed size listed: 7 x 12 in (18 x 30 cm)
Actual packed size: diameter 7 x 11 in (18 x 28 cm)
Picture at right courtesy of Cascade Designs

Quick & Dirty, Nitty Gritty

The Therm-a-Rest Navis is a pretty slick sleeping bag thing-y. Using a combination of my clothing, pad, and outerwear it is the main piece of a sleep system, allowing weight and volume to be shed from my pack. Usable in a wide range of temperatures it could be an all-season sleep system if I were in a warmer climate. I did use it for three seasons though. Please read on for the details.

Product Description

The Therm-a-Rest Navis Sleeping Bag (hereafter referred to as the Navis or bag) is the lightest offering in the company's new line of sleeping bags and blankets (quilts).

The outer shell is made of orange 30 denier nylon ripstop with a DWR (durable water repellent) finish. A swath of light grey nylon runs the length of the Navis on the right side. On the top left of the shell the bag's name and rating along with the Therm-a-Rest logo is embroidered.

Top of Navis

The bag has a trapezoidal footbox at the bottom. Attached to the shell at the end of the footbox are a couple tags. One is the standard consumer tag, with fill type, weight, materials, and "Made in China". The second, smaller tag has care instructions.

The Navis uses both styles of down chamber construction. The upper part uses sewn-through construction with the seams being 3.25 in (8 C) apart. They use the sewn-through here as this part corresponds to the user's coat/sweatshirt/fleece top so is expected to be bolstered the most for warmth.

For the remaining lower portion of the bag the down is placed in horizontal chambers separated by baffles made of 4-way stretch mesh. This is the warmest way to use down as it eliminates the possibility of cold spots at seams.

The lining is made of grey 30 denier nylon. It is a bit stiffer and coarse-feeling than I am used to feeling used for linings. Running around the top opening of the Navis is a huge 4 in (10 cm) down-filled draft tube to help keep cold air out and body heat in. There is a drawstring and cord lock on the right side of the bag that lets the opening be cinched closed. There are four loops inside the bag which are for drying inside out, and for possible optional liners or other gear down the road.


Flipping the bag over exposes a couple more features of the Navis that are shared across Therm-a-Rest's sleeping bag line. Two wide elastic loops are called SynergyLink Connectors. These keep the bag attached to a sleeping pad. But this is not just to keep it from sliding off; it also keeps the bottom insulation under the sleeper. Which is quite important as the Navis uses the sleeping pad to provide all of the bottom insulation of the sleep system. In the picture above the area with no seams where down is has no insulation. It is just a single layer of nylon between the user and the pad. This means that correct pad choice is important to have the right R-value for the temperatures expected.

To further accommodate side-sleepers the Navis has been constructed allow the bag to move vertically while still staying attached to the pad. This lets shoulders and hips be vertical instead of spread out flat like back-sleepers have, but does not compress the down by pulling the bag tight at these spots.

Stuff it and store it

The Navis comes with the tiny nylon stuff sack and mesh storage sack shown above. (It does not come with the 1 L bottle…)

When lying flat I measure the top opening of the Navis at 30 in (76 cm) wide, or I could say it has a top girth of 60 in (152 cm). I read a length of 68 in (173 cm) inside the bag.

Field Data

Here's light in your eyes.

I took the Navis on five Minnesota trips this past summer and fall, with most of the trips in fall so as to play with the "system" part more. It went twice to Smokey Hills State Park and three times on private land north of Halstad. All nights were spent in a tent on varying pads. Low temperatures were as follows; 55 F, 32 F (twice), 22 F and 0 F (13 C, -6 C, & -18 C). The picture above is from one of the 32 F (0 C) mornings.


For the past five years I have been very into using "sleep systems" as opposed to just a sleeping bag. By system I mean using a combination of pads, cover (quilt, bag, etc) headwear and clothing to complement each other and give a greater range of options for sleeping in the backcountry. The biggest reason for doing so is the weight and volume savings it gives.

When I first saw the prototype sleeping bags from Therm-a-Rest at the Outdoor Retailer show it was the Navis that piqued my interest the most. Being the owner of a Russian-made half bag (called an Elephant's Foot in Europe) that utilizes parkas and gloves for mountaineers in winter conditions, and numerous quilts that I take down to 0 F (-18 C) temps I was well familiar to the concept that they were preaching for the Navis. I told the rep at the show that I thought it would go over big-time with the UL (ultralight) crowd.

I really like the Navis. In summer I only used it a couple times as I was using a couple of other quilts (including one from Therma-Rest, see review here) that were made for the warmer temps. On those trips the Navis was great. At its warm rating it was great and I didn't need to wear anything to bolster it, but I do wear a very light baselayer and ultralight socks just to keep it clean. (I call them my back-country pajamas.) On these trips I used a NeoAir XLite pad (see review here) under it.

The Navis has the SynergyLink Connectors for attaching to a pad. As I use the large size pads I don't care for the hassle of getting them around my wider-than-normal pads. Plus years of quilt use have taught me to stay put on my pads anyway, so I did not put the straps to use.

Sleep system fall

Once the temps started dropping the avis really shone. At low temps it is even more comfortable that a quilt because there is no way for my foot to slip out into cold air since the bottom is attached. Heavy duty PJ'sWhile years of quilt use has made me pretty good at keeping my feet in I still pop them out once in a while, so I assume that this would be of comfort to those new at the lightweight sleep game. The first cold trip saw it used at a low of 32 F (0 C) in conditions that included rain, hail and our first snow of the season. I used a NeoAir XTherm pad underneath (see review here) and a medium weight baselayer and wool socks. On my head I wore a fleece beanie that has a pull-down face mask. I did not get cold enough to need the mask. I also brought a light insulated jacket, the Helly Hansen Odin Isolator. In the early morning hours I got cold enough to pull the jacket over me to add warmth to my upper torso and that was fine for the rest of the night.

The next trip I had the same combo (just a different baselayer top) but as this night dropped to 22 F (-6 C) I had to put the jacket on inside the bag and also wore thin fleece gloves. I was pretty comfortable although my legs were a little cold. I should have brought warmer baselayer bottoms. Here is a shot taken in the morning on that trip.

That is probably the lowest that the Navis really should be used at but I believe in putting gear to the torture test (or maybe I just like punishing myself...) so I took it out a couple of weeks later for our first dip to 0 F (-18 C) temps. On this trip in Smoky Hills State Forest I was set up for the cold with a Down Works Down Balaclava, Nunatak Down Mukluks (see reviews here), heavy fleece gloves, expedition weight fleece pants and a medium weight top. For a coat I used a Columbia medium weight down coat that I am beta testing which is why it is not in the picture below. Again I am on top of the XTherm pad. Believe it or not I was comfortable. At first I was even too warm but that was most likely because of just eating.

Winter gear

If I am being practical I would say that the Navis is a great base for a sleep system that runs from the height of summer's warm nights to spring and fall days that see lows down to 20 F (-7 C) with the right accessories. I am going to suggest it to UL and light-hiker friends who don't like the openness of a quilt but still want to try the system approach. I really am happy to see a major company like Cascade Designs (the parent of Therm-a-Rest) making a product aimed at us.

This report was created with the Report Writer Version 1.5 Copyright 2013. All rights reserved.

Read more reviews of Cascade Designs gear
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