The ENO (Eagles Nest Outfitters) Vulcan Under Quilt is a full length quilt filled with synthetic Primaloft Synergy insulation and has an integrated perimeter suspension system that is compatible with any gathered end hammock. Rated for 35-45 degree weather, it’s priced at $174.95, which is expensive when compared to other synthetic full-length underquilts like the Enlightened Equipment Prospect Unqerquilt ($165/65″/30 degrees) and the Arrowhead Equipment New River Underquilt ($155/78″/25 degrees).
The Vulcan is full length quilt as opposed to a partial length one, with an wrap-around elastic suspension system that you secure to the ends of a gathered-end hammock. Like other underquilts, it has a differential cut rather than a rectangular one, that conforms to curve of your body and hammock to improved weight-to-thermal efficiency.
What’s the advantage of a quilt filled with synthetic insulation, rather than goose down? The difference is primarily one of lower cost and larger packed size since a synthetic quilt will be bulkier and less compressible than one insulated with goose or duck down. As a for instance, the ENO Blaze Underquilt filled with 750 fill power duck down is rated for 30 degrees but costs just under $300 or about a 60% premium for a quilt that only weighs 1 ounce less than the Vulcan.
In testing the ENO Vulcan Under Quilt, I repeatedly experienced Cold Butt Syndrome every night I used it in its stated temperature range of 35-45 degrees. Cold Butt Syndrome or “CBS” occurs when your butt gets cold because your underquilt, sleeping pad, or foam pad (whatever you use for cold weather hammock insulation) doesn’t keep you warm. Based on my experience, there’s simply no way that the Vulcan is a 35-45 degree underquilt and I wouldn’t recommend taking it below 50-55 degrees without bringing along a foam pad to augment it.
After putting the Vulcan through its paces on multiple backpacking trips, I also discovered the specs published by the manufacturer on their website were way off and that the product I’d received was 5 ounces lighter (25 ounces instead of 30 ounces), 9 inches narrower (39 inches instead of 48 inches) and 70 inches long instead of 80 inches).
When I contacted ENO about the discrepancy (I try to give manufacturers a chance to put things right before I publish a bad review), they measured the Vulcans they had in stock and revised the measurements on their website, downsizing the product weight to 25 ounces and changing the online measurements to be 82″ x 45″ from 80″ x 48″, but not the 70″ x 42″ that I reported to them because their in-stock under quilts had different measurements than mine.
But with all of these spec changes, you have to wonder how the Vulcan’s 35-45 degrees temperature rating can remain the same after the weight of the quilt was reduced from 30 ounces to 25 ounces (scratching head). You need to wonder how many people bought quilts where the specs didn’t match up…
Regardless, I recommend giving the ENO Vulcan under quilt a pass. Too cold, not to mention the inaccurate product specs. ENO obviously have some production and quality control issues and I’d advise you to make sure that you verify the weight and measurements of the Vulcan Under Quilt if you buy or have already purchased one, to make sure it matches what you thought you were buying. ENO, to their credit has a two-year warranty, so call them up if your Vulcan doesn’t measure up.
If you want to buy a synthetic underquilt, I’d recommend you check out a cottage manufacturer like Enlightened Equipment or Arrowhead Equipment which both have more stringent quality controls in place because they sew each quilt on a custom basis for individual customers.
Disclosure: ENO (Eagles Nest Outfitters) provided Philip Werner (SectionHiker.com) with a Vulcan Under Quilt for this review.