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Fourth Element

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Fourth Element X-Core Vest

Fourth Element X-Core Vest

RRP $255.00 AUD

Our Price $218.00 AUD

You Save $37.00 AUD (15%)

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Product overview

About this product

The Fourth Element X-Core Vest is a specialised thermal core layer designed to provide additional warmth where divers need it most. Worn beneath a drysuit undersuit such as the Arctic X or HALO A°R, it increases insulation around the body's core while maintaining complete freedom of movement through the shoulders and arms.

Ideal for technical, recreational and cold-water diving throughout Melbourne, Victoria and southern Australia, the X-Core Vest allows divers to extend their thermal layering system without significantly increasing buoyancy or bulk. It is an excellent solution for longer dives, colder water temperatures and divers who feel the cold more easily.

The Fourth Element X-Core Vest is a heavyweight thermal core vest designed to add extreme warmth to the body's core during cold-water diving. Worn under an Arctic, HALO A°R or other drysuit undergarment, it boosts thermal protection without adding bulk around the shoulders and arms.

Made with Polartec® Power Stretch® fabric containing 76% recycled polyester, the X-Core Vest provides a snug four-way stretch fit, fast moisture wicking and excellent thermal performance. It can be worn over a lightweight baselayer such as J2 or Xerotherm, or directly next to the skin for focused core protection.

Available in men's and women's sizing. Most sizes are available to order with Australia-wide shipping.

Service and support

Shipping and specialist support

Why buy from Extreme Watersport

  • Extreme Core Warmth
  • Low-Bulk Vest Design
  • 76% Recycled Polyester

Shipping

Most sizes are available to order. If your selected size is temporarily unavailable from Fourth Element, we'll confirm the latest delivery estimate before processing your order. Australia-wide shipping available.

Lead time

Usually dispatched within 2–5 business days.

Technical construction

Focused Core Protection Without the Bulk

The X-Core Vest is built around a simple diving reality: when the body gets cold, it protects the core first. By adding heavyweight insulation around the torso, the X-Core helps extend comfort during cold-water dives while keeping the shoulders and arms free for movement.

It is designed to be worn over a lightweight baselayer such as Xerotherm or J2, or beneath a drysuit undersuit such as the Arctic or HALO A°R. For many divers, this extra core warmth can reduce the need for electric heating in moderate cold-water conditions.

Performance detail

Performance highlights

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Targeted Core Warmth

Provides exceptional insulation where your body needs it most, helping maintain core temperature during long cold-water dives.

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Perfect Layering Piece

Designed to be worn beneath Arctic, HALO A°R or other drysuit undersuits, or over a lightweight baselayer such as Xerotherm or J2.

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Maximum Mobility

Sleeveless construction reduces bulk around the shoulders and arms, allowing unrestricted movement while maintaining excellent thermal protection.

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Premium Technical Fabric

Constructed using Polartec® Power Stretch® with 76% recycled polyester, offering four-way stretch, fast moisture management and long-lasting comfort.

Specifications

Technical Specifications

Product
Fourth Element X-Core Vest
Layer Type
Core thermal vest / premium drysuit layering garment
Best Use
Cold-water diving, technical diving and extended drysuit dives
Material
92% Polyester / 8% Elastane (76% recycled polyester)
Fabric Technology
Polartec® Power Stretch® (bluesign® & OEKO-TEX® certified)
Fit
Slim fit with four-way stretch for close-to-body comfort
Key Features
Sleeveless design, extended body length, chest thermal panel and fast-wicking fabric
Thermal Performance
Heavyweight core insulation with minimal impact on buoyancy and mobility
Care Instructions
Machine washable.
Available Sizes
Men's and Women's standard sizes

The Fourth Element X-Core Vest is a premium thermal core layer designed to increase warmth without significantly increasing buoyancy or bulk. Using heavyweight Polartec® Power Stretch® fabric and a sleeveless ergonomic design, it provides focused insulation around the torso while maintaining complete freedom of movement for drysuit diving.

Fit guidance

Need help choosing your size?

Use the size guide below as a reference before ordering. If you are between sizes or plan to wear additional base layers, contact us and we can help recommend the most suitable fit.

Men's size guide
Fourth element size chart
Women's size guide
Fourth Element Women's Size chart

Included

What's Included

  • Fourth Element X-Core Vest

Product guidance

Product guidance

Why Choose the Fourth Element X-Core Vest?

The Fourth Element X-Core Vest is designed to increase warmth where it matters most: your body's core. By concentrating additional insulation around the chest and torso, it helps maintain core temperature without restricting movement or adding unnecessary bulk to the shoulders and arms.

Unlike wearing a heavier full-body undersuit, the X-Core Vest allows divers to fine-tune their thermal layering system, making it an excellent option for seasonal temperature changes, longer dives and divers who simply need a little extra warmth beneath their existing undersuit.

Perfect for Melbourne and Australian Cold-Water Diving

Water temperatures around Melbourne, Port Phillip Bay, Victoria and Tasmania often vary throughout the year. The X-Core Vest provides a simple way to increase thermal protection for colder dives while maintaining the flexibility and comfort of your preferred drysuit undersuit.

Whether you're shore diving, boat diving, instructor diving or completing long technical dives, additional core insulation can significantly improve comfort without affecting mobility.

Build a Modular Drysuit Layering System

The X-Core Vest is designed to be worn over a lightweight baselayer such as the Fourth Element J2 or Xerotherm, then layered beneath Arctic X, HALO A°R or other drysuit undersuits. This modular approach allows divers to adapt their thermal protection to changing water temperatures rather than relying on a single undersuit for every dive.

Who Should Consider the X-Core Vest?

The X-Core Vest is ideal for divers who already own a drysuit undersuit but occasionally require additional warmth. It is particularly popular with technical divers, CCR divers, instructors, underwater photographers and anyone completing longer dives where maintaining body temperature becomes increasingly important.

Why Buy from Extreme Watersport?

As an authorised Fourth Element dealer in Australia, Extreme Watersport provides genuine Fourth Element thermal systems backed by expert advice from experienced cold-water divers. We can help you build the ideal layering system using the J2, Xerotherm, X-Core Vest, Arctic X and HALO A°R to suit Melbourne, Victorian and Australian diving conditions.

Product help

Product FAQs

What is the X-Core Vest designed for?

The X-Core Vest is designed to provide additional insulation around your body's core, where maintaining warmth has the greatest impact on comfort during cold-water dives. It adds significant thermal protection without increasing bulk around the shoulders and arms.

Can I wear the X-Core Vest under an Arctic or HALO A°R undersuit?

Yes. The X-Core Vest is specifically designed to be worn beneath undersuits such as the Fourth Element Arctic X and HALO A°R. It adds extra core warmth while maintaining excellent mobility.

Can the X-Core Vest be worn directly against the skin?

Yes. While it performs exceptionally well over a lightweight baselayer such as Xerotherm or J2, the X-Core Vest can also be worn directly against the skin when additional core insulation is required.

Will the sleeveless design reduce warmth?

No. The sleeveless design intentionally reduces bulk around the shoulders and arms while concentrating insulation around the body's core, where maintaining temperature has the greatest effect on overall warmth.

Can the X-Core Vest reduce the need for heated undersuits?

For many divers, yes. When combined with an appropriate baselayer and premium undersuit, the X-Core Vest can provide enough additional insulation that electric heating may not be necessary in many cold-water diving conditions.

Is the X-Core Vest machine washable?

Yes. The X-Core Vest is machine washable. Following the manufacturer's care instructions will help maintain the performance and lifespan of the technical fabrics.

Need Help Building Your Thermal Layering System?

Choosing the right drysuit thermal system depends on your water temperature, dive duration and existing undersuit. If you're unsure whether the X-Core Vest is right for your diving, or you'd like advice on pairing it with Xerotherm, Arctic X or HALO A°R, our team is happy to help you build the ideal layering system.

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