The physiological response to cold stress is to reduce blood flow to the periphery and preserve the core temperature. During a dive, this means the body prioritises warmth at the core — but it can still become the limiting factor in safety and comfort.
The X-Core Vest delivers exceptional thermal protection to your core, enabling longer, more comfortable dives even in cold conditions.
Designed to be worn under an Arctic, Halo A°R or any other drysuit undergarment, X-Core significantly boosts thermal performance—often eliminating the need for electric heating. For best results, wear it over a lightweight baselayer such as the J2 or Xerotherm, or directly against the skin for maximum warmth.
The sleeveless design of the X-Core Vest reduces bulk and buoyancy, especially around the shoulders and arms, ensuring freedom of movement underwater.
Its four-way stretch fabric and elongated cut offer a snug, flexible fit that minimizes cold spots. A strategically placed chest panel blocks the rush of cold air from the inlet valve, providing extra insulation in a key exposure area.
The fast-wicking inner fabric efficiently transfers perspiration to the outer layer, keeping the diver drier, warmer, and more comfortable throughout the dive.
Key Features
- Exceptional warmth and comfort
- Contains 76% recycled polyester
- Four-way stretch fabric for a snug fit
- Ideal worn next to skin or over a baselayer
- Fast-wicking fabric keeps you dry and warm
- Heavyweight construction for maximum insulation
- Polartec® Power Stretch® – BlueSign® and Oeko-Tex® certified
- Odour-resistant and machine washable
Fabric & Care
Composition: 92% Polyester / 8% Elastane (76% recycled polyester)
Care: Machine washable.
Fit Guidance
Fit type: Slim fit
Model 1: Tyla wears size Small (Height 5’8” / Chest 33” / Waist 23” / Hips 34”)
Model 2: Tiri wears size Large (Height 5’9” / Chest 36” / Waist 30” / Hips 40”)
Related Underwater Gear Categories:
- Extensive Collection of Scuba Equipment
- Comprehensive Range of Fourth Element gear
- Wide Array of Rash Guards and Dive Skins
- Dive Travel Packages with Bluewater Dive Travel
Detailed Specifications
| Product Type | Women's Thermal Undergarment Vest |
| Intended Use | Additional thermal layer for drysuit diving |
| Thermal Protection Level | High – designed to maintain core warmth in cold-water conditions |
| Material | 92% Polyester / 8% Elastane (76% recycled polyester content) |
| Fabric Technology | Polartec® Power Stretch® – heavyweight four-way stretch, wicking, and insulating |
| Certifications | BlueSign® and Oeko-Tex® certified for responsible and safe production |
| Fit | Slim fit, sleeveless design with extended torso length for added coverage |
| Features | Odour resistant, moisture-wicking, machine washable, soft brushed inner surface |
| Recommended Layering | Best worn over Xerotherm or J2 baselayers, or directly next to skin |
| Weight | Heavyweight (approx. 0.45 kg / 1.0 lbs shipping weight) |
| Sustainability | Made with 76% recycled fibres; designed for durability and long product life |
| Manufacturer | Fourth Element Ltd – UK |
| Care Instructions | Machine wash cold, gentle cycle. Do not tumble dry. Avoid fabric softeners. |
- 1 × Fourth Element Women's X-Core Vest
- Reusable protective packaging
Women's Size Guide
Body measurements. Ranges shown in cm with (inches) in brackets.
| Size | Height (cm/in) | Chest (cm/in) | Waist (cm/in) | Inside Leg (cm/in) |
|---|---|---|---|---|
| XX Small | 160–168 (63–66) | 68–76 (27–30.2) | 51–59 (20–23) | 71–75 (28–29.5) |
| X Small | 162.5–170 (64–67) | 74–82 (29.2–32.3) | 57–65 (22.5–25.5) | 73–77 (28.5–30.5) |
| Small | 165–173 (65–68) | 80–88 (31.5–35.2) | 63–71 (25–28) | 75–79 (29.5–31) |
| Medium | 167.5–175 (66–69) | 86–94 (34–37.2) | 69–77 (27–30.5) | 77–81 (30.5–32) |
| Large | 170–178 (67–70) | 92–100 (36–40.2) | 75–83 (29.5–32.5) | 79–83 (31–32.5) |
| X Large | 172.5–180 (68–71) | 98–106 (38.5–42.2) | 81–89 (32–35) | 81–85 (32–33.5) |
| XX Large | 172.5–180 (68–71) | 104–112 (41–44.2) | 87–95 (34.5–37.5) | 81–85 (32–33.5) |
| XXX Large | 172.5–180 (68–71) | 110–118 (43.5–47.2) | 93–101 (36.5–40) | 81–85 (32–33.5) |
Why Buy from Bluewater
1. Proof of Expertise
- Authorized Fourth Element dive gear dealer — full manufacturer warranty.
- Founded and staffed by active divers, underwater photographers, and explorers.
- Decades of combined hands-on experience with the gear we sell.
- We test and use most of the equipment ourselves before recommending it.
2. Risk-Free Purchase (See Terms Of Service)
- 30-day, hassle-free returns (unused condition).
- Secure payment with trusted gateways (credit card, PayPal, etc.).
- All products shipped in factory-sealed boxes (unless stated).
- Transparent policies — no hidden fees or fine-print surprises.
3. Fast & Reliable Delivery
- Free U.S. shipping over $200 for Photo Gear & $50 for Dive Gear.
- Same-day dispatch on in-stock orders placed before 12pm.
- Worldwide shipping options with reliable carriers.
- Real-time tracking updates sent straight to your inbox.
4. Extra Value at No Extra Cost
- Lifetime product support by email, phone, or in-store.
- Setup help & usage tips tailored to your needs.
- Exclusive buyer’s guides, tutorials, and dive trip invitations.
- Early access to special promotions & new releases.
5. Social Proof & Community
- Thousands of satisfied divers & underwater photographers worldwide.
- 5-star average product & service ratings.
- Active in dive events, conservation projects, and photography competitions.
6. Personal Connection
- Direct line to our in-house experts — no outsourced call centers.
- Friendly, passionate staff who speak “diver” fluently.
- We care about your whole adventure, not just the sale.
We offer lifetime support with all purchases.
Please call or email us with any questions; our knowledgeable staff would love to assist you.
