Santi BZ400 Heated Undersuit – Maximum Thermal Protection for Cold Water Drysuit Diving

The Santi BZ400 Heated Undersuit is engineered for demanding divers who need exceptional thermal insulation and integrated heating capability beneath a drysuit. Built from BZ400 Thinsulate material and enhanced with a new generation of durable, flexible heating wire, this heated undersuit delivers long-lasting warmth - even when battery levels drop. With ergonomic cable routing, integrated glove connections, and compatibility with Santi's latest thermovalve systems, it is the ultimate solution for extended cold water exposure.

Key Features and Benefits

• Durable, Flexible Heating System
  New generation of heating wire encased in ultra-soft, silicone insulation resists breakage and delivers reliable heat.

• Cut-Resistant Power Cables
  Synthetic wire sheathing withstands abrasion, high temperatures, and mechanical wear - ideal for demanding dive conditions.

• Safe and Regulated Heat Output
  Equipped with a built-in safety switch to prevent overheating and current surges.

• Powerful and Efficient
  110 watts of output; runtime varies by battery: ~1–1.2 hours (10Ah), ~2–2.5 hours (20Ah).

• Max Heat Output
  Capable of reaching 113°F (45°C) at full power, delivering serious warmth when you need it most.

• Ergonomic Design and Internal Layout
  Redesigned cable positioning and fit improve comfort and reliability during long dives.

• Integrated Glove Connectors
  Pre-wired for direct connection to Santi heated gloves - no additional modifications needed.

• Undersuit Storage Bag Included
  Keeps the garment protected and organized during travel and storage.

• CE Certified
  Meets European safety and performance standards.

Detailed Description

The Santi BZ400 Heated Undersuit is built for extreme thermal demand in drysuit diving. Whether you're conducting deep decompression dives, ice diving, or long-range exploration dives in frigid conditions, this undersuit ensures constant warmth and thermal stability. Even in low battery conditions, the insulation properties of the BZ400 material provide passive heat retention, making it more than just an active system - it’s also an excellent standalone undergarment.

The heating elements are enclosed in new-generation silicone insulation, delivering high flexibility without compromising durability. Synthetic power wires are cut- and heat-resistant, increasing longevity and minimizing failure points in harsh environments. The ergonomic internal cable layout improves fit and movement underwater.

Designed to be used exclusively with Santi’s new thermovalve and connector system (not compatible with older systems or >12V batteries), the BZ400 Heated Undersuit for drysuit divers also supports direct connection to Santi heated gloves. It includes a dedicated storage bag and is available in a full range of men’s and women’s sizes, with made-to-measure (MTM) options available.

Specifications

• Material: BZ400 Thinsulate

• Heating Power: 110 watts

• Max Temperature: 45°C / 113°F

• Runtime: ~1–1.2 hrs (10Ah) / ~2–2.5 hrs (20Ah)

• Safety Features: Overheat protection and current regulation

• Connectivity: Compatible with Santi thermovalve and connector. Do not combine with other connectors or batteries higher then 12V.
  

• Included: Undersuit, integrated glove cables, undersuit bag

• Certification: CE certified

• Sizes Available:
  

  • Men’s: XS to XXXL (incl. short and long variations)

  • Women’s: XS to XXL

  • MTM: Made-to-measure available

  • Size Chart Here. All measurements in centimeters.

Stay warm in your drysuit even in the harshest underwater conditions with the Santi BZ400 Heated Undersuit. Designed for serious divers pushing thermal limits, it combines smart insulation, reliable heating, and ergonomic design. Choose your size or request MTM, and dive warm no matter where your dive takes you.