Sea To Summit Ultra-Sil Nano Poncho Review

Last Updated on 21/10/2023


In this Sea To Summit Ultra-Sil Nano Tarp Poncho Review, I share the results of testing this waterproof poncho in humid, wet conditions. You will learn how it performs when you are wearing a backpack over it, as well as how it performs when covering you and your pack.

Sea to Summit specializes in creating useful products that are tailor-made for lightweight hiking, camping, and backpacking. They make everything from eco-friendly travel soap infused with insect repellent to tents and sleeping bags with the warmest warmth-to-weight ratios on the market.

This silicon-infused poncho is their premium model, which offers unbeatable weight, size, and waterproofing.

Sea To Summit Ultra-Sil Nano Poncho Review Summary

In a hurry? Here is a brief overview of my Sea To Summit Ultra-Sil Nano Tarp Poncho Review with the pros and cons.

If you know me, you’ll know that I am a big poncho fan. I rate this as the best poncho for hiking in the world right now. Here’s why.

It is so lightweight and compact that you can take it anywhere, even if you don’t have a backpack. The material is totally waterproof and feels very soft as opposed to stiff. If you want a rain poncho that replaces the need to carry heavy and bulky waterproof jackets and pants, as well as a backpack cover, this is it.


Pros of the Sea To Summit Ultra-Sil Nano Poncho Tarp

Here are the main benefits of the Sea To Summit Ultra-Sil Nano Poncho:

  • Versatility: The poncho serves multiple functions, acting as a waterproof ‘jacket’, pack cover, and tarp.
  • Lightweight: Made from 15D Ultra-Sil Nano fabric, this poncho is designed to be incredibly lightweight, making it easy to carry and ideal for lightweight backpacking.
  • Compact: It packs down incredibly small, saving valuable space in your backpack.
  • Waterproof: The 15D Ultra-Sil Nano fabric is 100% waterproof, providing reliable protection from rain.
  • Large Coverage: It’s designed to accommodate a large backpack under the poncho, keeping both you and your gear dry.
  • Ventilation: The open sides and loose fit allow air to circulate better than a waterproof jacket.
  • Secure Attachment Points: The poncho features guy attachment points, which means it can be stretched out to create a more stable and taut shelter.
  • Quality Construction: Double stitched, tape-sealed, and with a 3-panel hood construction.

Cons of the Sea To Summit Ultra-Sil Nano Tarp Poncho

Here are the main downsides of the Sea To Summit Ultra-Sil Nano Tarp Poncho:

  • Material Thickness: The 15D fabric, while lightweight, may not be as durable as heavier, more robust materials.
  • Size Fit: Because it’s designed to fit over a large backpack and be used as a tarp, it might be too long if you’re not that tall.
  • Condensation: Even though it has amazing ventilation in humid weather, it does suffer from condensation when hiking uphill.

Features and Specifications

Here are the specifications and features of the Sea To Summit Ultra-Sil Nano Tarp Poncho:

Sea to Summit Ultra-SIL Nano Tarp Poncho 4-in-1 Raincoat, Pack Cover, Groundsheet, and Shelter, Pacific Blue


  • WEIGHT: 8.1 oz / 230 g
  • PACK SIZE: 3 x 5.25 in / 7.5 x 13.5 cm
  • SIZES: One size fits all
  • DIMENSIONS: 57 x 104 in / 145 x 265 cm
  • MATERIAL: 15D Ultra-Sil Nano fabric
  • Accommodates a large backpack
  • It easily converts from a poncho to a tarp or ground sheet
  • Durable side snap clips create half sleeves or keep your arms inside in heavy rain
  • Double-stitched, tape-sealed
  • 3-panel hood construction with adjustable toggles and peaked brim

Ultrasil poncho sea to summit review

Weight and Pack Size

The Sea To Summit Ultra-Sil Nano Tarp Poncho has to be the most lightweight and packable waterproof shell you can reliably use for hiking. It is a similar pack size and weight to a 6-inch Subway sandwich to give you an idea. 3 x 5 inches is nothing, and you won’t even notice the weight of 8 ounces.

If you are traveling or hiking in hot and humid climates like Asia or South America, then you don’t really want to carry a load of unnecessary items like waterproof jackets, pants, and pack covers just in case it rains. This lightweight and compact poncho does away with all of that and is the ideal emergency rain cover.


Fit and Sizing

For reference, I am 5 ft 10 inches, and as you can see from the pictures, it fits down to just below my knees.

There are two ways to put on the Ultra-sil Nano Poncho: unsnapped or snapped. It’s easier without the buttons snapped shut as you simply pop your head through the central hole and fasten it up once on. The time-saving way is to leave the buttons snapped shut. 

When I first tried the Sea To Summit Ultra-Sil Nano Tarp Poncho, it did feel big, but I soon got used to it. Sometimes, while hiking, the extra material was annoying (on steep inclines with a heavy pack), and other times, it felt like a blessing (whenever there was a breeze). I found three solutions to this.

The first thing that helped was wearing a backpack over the top of the poncho, which brought it in around the shoulders and allowed you to tuck it around the back. But this means your bag gets wet. The next option is wearing a backpack under the poncho, which helps to fill the extra space. The last option isn’t ideal but involves wearing a belt on the outside of your poncho.



I have nothing bad to say about the waterproofing of the Sea to Summit Ultra-Sil Nano Poncho. It is 100% waterproof thanks to the siliconized material, which makes it impossible for water to pass through.

Because of its long cut and design, this poncho protects your entire upper body and backpack, as well as your upper legs. When it isn’t raining too hard, the ponch also acts as a bit of an umbrella for your lower legs too. It’s the all-in-one rain protection no one is talking about (apart from us!).

The hood is seam-sealed and has an adjustable toggle as well as a peaked hood, so you can adjust it to keep rain out of your eyes. The sleeves are long enough to protect most of your arms, or you can keep them tucked inside if it rains heavily.


Breathability and Ventilation

This is where things get tricky because it has amazing ventilation but not-so-great breathability. What this means is that air can circulate through the gaps in the sides and bottom, but the material does such a good job of blocking moisture that it doesn’t allow condensation to escape through the pores (like with Goretex).

You can wear the poncho with just one stud fastened at the top on each side for your arms to go through. This provides maximum ventilation and reduces the need for breathability in certain weather. The only time I found the poncho struggled was in hot, wet/humid weather with little to no wind. But compared with using a raincoat instead, it is no worse and, in fact, better in many ways.

sil-nylon poncho


Despite the material only being 15 dernier thick, it is incredibly durable for its weight. So much so that you can use it as a ground sheet to sit on wet grass or as a tarp shelter for up to two people without fear of it ripping. You still need to be careful not to snag it on anything sharp as you push through rugged undergrowth, but to say it is almost see-through, the toughness will, I think, surprise anyone.

Comfort and Practicality

poncho homer simpson

Comfort-wise, wearing this poncho is how I imagine Homer Simpson felt when he weighed 300 lbs and started wearing a dress. The Ultra-Sil Nano Poncho is so light and breezy that you could quite comfortably wear it all day if you had to. The only issue is that with so much loose material, it can be impractical for certain activities and get in the way at times. But this is the sacrifice I am willing to make.

The material is soft and flexible, which improves comfort and also reduces friction and noise. Thinking about it, maybe the quietness of the poncho is why I like it so much. It doesn’t rustle or sound like an empty chip packet, and on a long-distance hike in bad weather, it helps.


Using the Sea to Summit Nano Poncho as A Tarp Shelter

Truth be told, I hadn’t spent the night under this just because where I live, the mosquitos are really bad right now, but I set it up to see how it performed when I stretched it out. I have slept under a poncho for multiple weeks before, so I know exactly what it’s like.

With two hiking poles and two guylines, you can create a simple lean-to shelter for two people or as an A-frame if you are on your own. You simply sinch the hood shut in the middle and use the eight attachment points to secure it however you see fit. This is good enough to sleep in and can be used as your primary shelter as well as your waterproofs on fast and light excursions.

Of course, you don’t just have to sleep under it. You can use it as a social gathering space or to cook under, as well as a temporary shelter to escape a brief rain storm.


Using It Over a Backpack

One of the reasons I love using the Sea to Summit Ultra-Sil Nano Poncho for hiking is that it also covers your backpack as well as most of your body. So you can easily throw it on if it starts to rain and take it off once it stops, all without having to take your pack off or struggle with pack covers.

It easily fits over a large backpack without even undoing it, although sometimes it can get caught at the back and requires a little shake. It keeps your bag and all its contents dry in the heaviest rain and is more effective than any waterproof bag cover. A fully waterproof bag, on the other hand, is even better.


Is the Sea To Summit Ultra-Sil Nano Poncho Worth it?

The Ultra-Sil Nano Tarp Poncho from Sea to Summit is absolutely worth the money if you prioritize weight, pack size, and performance. Even though it costs more than other ponchos, it still offers the best value for money as it does what no other poncho can do.

Sure, the disposable ponchos you can get weigh the same and pack down as small, but they will only last one or two outings before they get wrecked beyond repair. This will last for many years and has multiple functions that make it way more valuable than a waterproof shell jacket.

Final Verdict

The Sea To Summit Ultra-Sil Nano Tarp Poncho is the most lightweight, packable, comfortable, and waterproof poncho I have ever tested. It is soft and flexible, which also makes it quiet instead of like two chip packets rustling together. It serves a niche market of people who want the most out of their gear and prioritize weight and pack size as highly as performance.



Sea To Summit Ultra-Sil Nano Poncho Review

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This article has been written and/or edited by Andrew N. 20+ years of hiking, mountaineering, and camping experience, with access to all the latest outdoor gear.

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