Expedition Baselayers

O'Neill Thermo X Long Sleeve Rash Guard

SKU: ONLTXLTSM

^$71.95

In Stock

DESCRIPTION

A high-performance long sleeve rash guard with incredible insulation, low bulk, and quick-dry properties for ultimate comfort and freedom of movement.

Fourth Element Arctic Men's Leggings

2 reviews

SKU: FRTXT500LSSB

~~$225~~ Save: $185.03 (82%)

^$39.97

+ wishlist

In Stock

DESCRIPTION

A minimalist design fleece undergarment for men with exceptional thermal protection and flat-stitched seams.

Bare Ultrawarmth Base Layer Pants for Men

2 reviews

SKU: BREMUWBLP3XL

^$102.95

+ wishlist

In Stock

DESCRIPTION

A highly-rated, advanced base layer pants for men that use OMNIRED Infrared Technology for ultimate warmth and moisture control.

Bare Ultrawarmth Base Layer Top for Men

2 reviews

SKU: BREMUWBLTMD

~~$124.95~~ Save: $18.74 (15%)

^$106.21

+ wishlist

In Stock

DESCRIPTION

A men's base layer top with OMNIRED infrared technology and advanced stretch-breathable fleece material for ultimate dry suit layering.

Fourth Element XT250 Xerotherm Top Men's

1 reviews

SKU: FRTXTM3XL

~~$203.70~~ Save: $30.55 (15%)

^$173.15

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In Stock

DESCRIPTION

A men's base layer top made with Xerotherm insulation technology and Polartec Powerstretch fabric.

Bare ExoWear Long Sleeve Top Men's, Black

1 reviews

SKU: BRETMSM

~~$179.95~~ Save: $26.99 (15%)

^$152.96

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In Stock

DESCRIPTION

A 2mm black long sleeve top for men with maximum thermal protection and neutrally buoyant exposure.

Waterproof Body 2X Top, Men's Undergarment

1 reviews

SKU: WPGBD2XTMMD

~~$198~~ Save: $29.70 (15%)

^$168.30

+ wishlist

In Stock

DESCRIPTION

A technically advanced men's undergarment with high thermal insulation and excellent moisture-wicking properties.

Fourth Element XT250 Xerotherm Leggings

SKU: FRTXLM3XL

~~$203.70~~ Save: $103.73 (51%)

^$99.97

+ wishlist

In Stock

DESCRIPTION

A fast-wicking, layering leggings with Xerotherm insulation technology and stirrups to prevent ride up.

Fourth Element J2 Men's Pants

SKU: FRTJ2MPM

^$154

+ wishlist

In Stock

DESCRIPTION

A sustainable and anti-microbial base layer pants for men, providing prolonged thermal performance and moisture-wicking design.

Fourth Element J2 Men's Long Sleeve Top

SKU: FRTJSMM

^$154

+ wishlist

In Stock

DESCRIPTION

A moisture-wicking, anti-microbial long sleeve base layer made from recycled polyester for superior warmth and comfort.

Fourth Element Xerotherm Men's Pants

SKU: FRTXTMPL

^$237

+ wishlist

In Stock

DESCRIPTION

A high-performance men's baselayer pant made from Polartec Powerstretch nylon and polyester for superior insulation.

Fourth Element Xerotherm Men's Top

SKU: FRTXTMTXL

^$237

+ wishlist

In Stock

DESCRIPTION

A lightweight, moisture-wicking men's thermal top made from nylon and polyester for superior drysuit insulation.

Fourth Element J2 Men's Shorts

SKU: FRTJ2SM2XL

~~$92~~ Save: $13.80 (15%)

^$78.20

+ wishlist

In Stock

DESCRIPTION

A high-performing, eco-friendly base layer shorts for men, designed for prolonged comfort and thermal performance.

Fourth Element J2 Men's Short Sleeve Top

SKU: FRTJ2MS2XL

~~$85~~ Save: $12.75 (15%)

^$72.25

+ wishlist

In Stock

DESCRIPTION

A men's short sleeve top made from OceanPositive recycled fabric, providing prolonged thermal performance and anti-microbial freshness.

Fourth Element X-Core Men's Vest

SKU: FRTXC2X

~~$209~~ Save: $31.35 (15%)

^$177.65

+ wishlist

In Stock

DESCRIPTION

A sleeveless men's vest with 4-way stretch fabric and Polartec X core technology for added warmth.

Fourth Element J2 Women's Pants

SKU: FRTJ2WPXL

~~$154~~ Save: $23.10 (15%)

^$130.90

+ wishlist

In Stock

DESCRIPTION

A sustainable and anti-microbial base layer pant for women divers seeking prolonged thermal performance and comfort.

Fourth Element Xerotherm Women's Top

SKU: FRTXTWTM

~~$237~~ Save: $35.55 (15%)

^$201.45

+ wishlist

In Stock

DESCRIPTION

A women's thermal diving top made with Polartec Powerstretch for superior insulation and moisture wicking.

Apeks ThermiQ Carbon Long Sleeve Top for Men

SKU: APXTLWMMD

~~$149~~ Save: $49.03 (33%)

^$99.97

+ wishlist

In Stock

DESCRIPTION

A men's scuba top with triple layer soft shell, graphene wrapped fibers, and thermal insulation.

Waterproof Body X Top, Men's Undergarment

SKU: WPGBDXTMXS

~~$138~~ Save: $20.70 (15%)

^$117.30

+ wishlist

In Stock

DESCRIPTION

A technically advanced men's undergarment with high thermal insulation and excellent moisture-wicking properties.

Lavacore Men's Long Sleeve Shirt

23 reviews

SKU: LVCSLSMXL

^$129.95

+ wishlist

In Stock

DESCRIPTION

A men's long sleeve shirt with antibacterial fleece lining for warmth and odor control, suitable for scuba diving.

Pros

Effective sun protection
High quality material
Provides excellent warmth
Recommended by dive instructors
Comfortable fit

Lavacore Men's Full Suit

20 reviews

SKU: LVCMLR

^$249.95

+ wishlist

In Stock

DESCRIPTION

A technically advanced fullsuit made with Lavacore fabric for thermal control and superior comfort.

NeoSport 1.5mm Xspan Men's Long Sleeve Top

20 reviews

SKU: NSPPLSSXS

~~$91.95~~ Save: $20 (22%)

^$71.95

+ wishlist

In Stock

DESCRIPTION

A ultra-soft and comfortable men's long sleeve top made from exclusive XSPAN material.

NeoSport 1.5mm Xspan Unisex Pants

18 reviews

SKU: NSPPPXS

~~$114.95~~ Save: $23 (20%)

^$91.95

+ wishlist

In Stock

DESCRIPTION

A 1.5mm XSPAN unisex pants with 4-way stretch neoprene, shock-cord waistband, and reinforced seat area.

Cressi Hunter Rash Guard Pants

18 reviews

SKU: CSBHPGRSM

^$57.45

+ wishlist

In Stock

DESCRIPTION

A loose-fit, mimetic-colored rash guard pant with reinforced knees and UV protection for scuba and spearfishing.

Lavacore Women's Full Suit

17 reviews

SKU: LVCW6

~~$249.95~~ Save: $37.49 (15%)

^$212.46

+ wishlist

In Stock

DESCRIPTION

A female-specific fullsuit with antibacterial fleece, 4-way stretch, and flat lock stitching for reduced water flow.

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Expedition Baselayers

When planning for extended time in cold or unpredictable environments, the right baselayer is more than just a comfort—it's essential for safety and performance. Expedition baselayers are purpose-built to manage moisture, regulate body temperature, and provide reliable insulation, all while maintaining a low profile under heavier gear. Whether you’re prepping for early summer dives in brisk northern waters, embarking on a spring expedition to glacier-fed lakes, or venturing into high-altitude environments where temperatures can drop suddenly, these baselayers serve as your first line of defense against the elements. The best expedition baselayers use advanced fabrics designed to wick sweat away from the skin, minimizing that clammy chill you get after surfacing or during surface intervals. Features like flatlock seams, articulated panels, and stretchy, quick-drying materials ensure that the fit is both snug and flexible, moving with you through every reach, kick, and climb. For divers, snorkelers, and outdoor adventurers who know the discomfort of shivering through a surface break or the fatigue that comes from losing heat too quickly, investing in a high-quality baselayer is a smart and practical choice.

Expedition baselayers also make thoughtful gifts for anyone with a passion for adventure—whether they’re training for their first cold-water certification, planning a remote kayaking trip, or simply love exploring the outdoors in every season. They’re the kind of gear that gets used again and again, appreciated each time the weather turns or a trip takes an unexpected turn toward the chilly. Some divers keep a dedicated set in their gear bag, ready for those spontaneous early morning dives or travel to destinations where water temperatures can be deceivingly cool even in late spring. The versatility of these baselayers means they’re not just for the most extreme conditions; they’re equally useful under wetsuits in temperate waters, as standalone layers during surface intervals, or even as cozy sleepwear in a drafty expedition tent. When considering which baselayer to choose, pay attention to the expected temperature range, your own tolerance for cold, and the fit you prefer—some like a close, compression-style fit for maximum heat retention, while others opt for a looser cut for breathability and layering flexibility. And for those planning to push further north or tackle truly frigid environments, it’s worth exploring our complete collection of Arctic Expedition Gear to ensure you’re fully prepared from head to toe.

As the days grow longer but water temperatures remain cool, May is a season of transition—ideal for adventures that demand adaptable, high-performance gear. Expedition baselayers play a quiet but pivotal role in keeping you warm and focused, whether you’re descending into kelp forests, trekking along windswept coastlines, or gearing up for a multi-day paddle through icy fjords. The best baselayers become trusted companions, forming the foundation of your kit and allowing you to extend your time outdoors, push your limits, and make the most of every journey. They’re an investment in comfort, safety, and the freedom to explore, no matter what the forecast holds.