[Product] Review | CleverHiker

Bottom Line

When all other base layers are too warm or light, the Icebreaker Merino Oasis 200 fills the gap. This well-rounded base layer offers slightly more warmth than most midweight options. The soft merino wool is comfortable against the skin while providing moderate insulation – perfect for hiking in shoulder seasons. It stands out as a versatile performer across a range of activities, from hiking and skiing to casual wear.

While the Oasis 200 scores solidly across all categories, it’s not the fastest at drying. Those engaging in high-output activities may notice that it takes longer to manage moisture than other options. However, the wool’s natural odor resistance and breathability add to its appeal for extended wear.

Overall, the Icebreaker Merino Oasis 200 is a solid, reliable choice for those seeking a slightly warmer base layer with the benefits of merino wool. We chose to test the Oasis 200 on a thru-hike of the Colorado Trail due to its versatility and slight warmth bonus over other lightweight base layers on our list. It held up beautifully even on frigid nights above treeline.

Comfort

The Oasis 200 is a comfortable wool base layer with a relaxed fit and thoughtful features. It fits true to size and is cut right between relaxed and snug. We appreciate that the crew neck is a little larger than most, but it might not be everyone’s cup of tea.

Merino wool can sometimes be itchy, but the soft wool of the Oasis 200 is very comfy against the skin. The flatlock seams are completely unnoticeable and the shoulder seams are shifted forward to reduce friction and stay clear of backpack straps. This top also features gusseted underarms to help with freedom of movement. If you like to tuck your base layer in, the extended drop tail provides plenty of extra material to keep it in place.

The overall fit of the Oasis 200 is comfy, soft, and mobile, but we found one little flaw in layering. When we layered it under a mid-layer and insulating layer, it tended to bunch up a little bit. However, we tried pretty hard to get it to wedgy with jumping jacks, yoga, and pushups. The bunching was mild but worth noting.

Warmth

The Oasis 200 fills a nice sweet spot in warmth between lightweight and midweight base layers. Most lightweight base layers have a fabric weight of about 120-180 grams per square meter. The Oasis 200 bumps that up a hair to 200g/ms – a key factor in our decision to use it on a Colorado Trail thru-hike. Although warm, it still feels like a lightweight base layer as far as fit and drape goes. At just 7.6 ounces, it’s one of the lightest base layers we tested.

The extra fabric weight extends the Oasis 200 usage into cold weather territory. We’ve used it as a sleeping layer down to about forty degrees Fahrenheit, a chilly weather hiking layer, and it makes a great base layer for ski season as well.

Breathability

While the Oasis 200 isn’t the fastest drying base layer in the bunch, it feels flowy and breathable. When we put it through our drying test by making the layer wet and timing how long it took to feel dry to the touch, it performed a bit below average compared to the rest of the layers.

However, breathability isn’t all about drying time. Some layers dry faster than others without letting as much wind through. When worn as a standalone layer, the Oasis 200 felt as breezy as lightweight layers, even with its added warmth. It allows just enough breeze to provide some evaporative cooling but not enough to leave you shivering. The relaxed fit also contributes to its breezy, flowy feel.

The Oasis 200 is made with 100% merino wool, a naturally moisture wicking and temperature regulating material. This means that while the base layer is drying, it wicks moisture away from the skin, reducing that soggy chill from a sweaty shirt. Overall, the Oasis 200 strikes a happy medium in terms of breathability.

Versatility

The Oasis 200 shines with its remarkable versatility. If you look solely at numbers, it doesn’t stand out above the other layers in any category. Instead, it ranks as a solid choice all across the board. It’s not too warm or too lightweight and doesn’t sacrifice comfort.

Had it conformed to the fabric rate of most lightweight base layers, the Oasis 200 would be more precisely targeted toward two to three-season viability. However, the added fabric weight of 200g/ms makes it a great choice all year round. The naturally odor-resistant wool also makes it a solid option for extended wear, on a thru-hike or a multi-day mountaineering expedition.

We would love to see a few extra features to enhance this layer’s functionality even further. The Oasis 200 keeps it simple and minimalist, but some thumb loops would be a welcome addition. However, despite its lack of added features, the Oasis 200 could very well be a do-it-all base layer year-round.

Style

We’re not trying to tell you what to wear to your company’s wine mixer, but the Icebreaker Oasis 200 wouldn’t be our first choice. The fit and aesthetic are a little pajama-like, which is great for camping, hiking, and lounging around the house, but it isn’t going to win any fashion awards. The extended drop tail is another feature that adds more coverage but perpetuates the pajama aesthetic.

We do appreciate the variety of color options available for this base layer. It includes neutral colors, pastels, and even brighter, more vibrant colors. Whatever your style, you will likely find something you like in the Oasis 200’s colorways.

Overall, the Icebreaker Merino Oasis 200 is built for function over fashion while offering plenty of color options.

Should You Buy the Icebreaker Merino Oasis 200?

The Icebreaker Merino Oasis 200 is a comfortable and versatile wool base layer offering more warmth than many lightweight options. Its soft merino wool feels great against the skin, with flatlock seams and gusseted underarms – enhancing overall comfort and mobility. The relaxed fit and drop-tail design provide excellent coverage, though some may notice slight bunching when layered.

For outdoor enthusiasts looking for an all-around base layer, the Oasis 200 performs well across the board, from hiking to skiing. The 100% merino wool offers natural odor resistance and temperature regulation. While it’s not the fastest-drying layer, it provides solid breathability, allowing enough airflow to keep you cool without compromising warmth.

The Oasis 200 offers excellent value for those seeking a reliable, year-round option. However, it’s not ideal for those who need rapid moisture management or prefer a more fitted look. It’s best suited for those prioritizing comfort, warmth, and versatility over high-performance technical features.

What Other Base Layers Should You Consider?

Smartwool Classic All-Season Review: The Classic All-Season is more typical of a lightweight base layer. It offers more breathability and a faster drying time while sacrificing some warmth.

Patagonia Capilene Midweight Crew Review: If synthetic fabrics are more your bag, the Capilene is comparable in weight and breathability to the Oasis 200, but in synthetic form. It dries more quickly and features handy, low-profile thumb loops.

Ortovox 185 Merino Rock’n’Wool Review: The Rock’n’Wool has the best warmth-to-weight ratio of any base layer we tested. It’s lighter than the Oasis 200 and traps heat more effectively. The trade-off is it is much less breathable.

Smartwool Classic Thermal Review: Maybe the added warmth of the Oasis 200 made you feel warm and fuzzy and left you wanting a true midweight, wool base layer. The Classic Thermal is similarly versatile and comfortable but is notably more cozy.