High Density Polyethylene (HDPE) is the next generation boat-building material, with unparalleled safety and durability properties.

HDPE outperforms alternative watercraft alloy or composite materials:

  • Personnel safety: superior impact and vibration absorption reducing personnel fatigue
  • Incredibly durable and impact-resistant
  • Positive buoyancy offering premium stability
  • No corrosion, electrolysis, or delamination
  • UV stable and fouling resistant
  • In-situ repairs with no hot works required
  • Lasts up to four times longer than alternative materials with comparable gross weight


The high-density polyethylene (HDPE) vessels combine the best of materials technology with Australian design ingenuity and an innate knowledge of local conditions.

HDPE is our boatbuilding material of choice for The Sentinel family of tactical defence vessels, not least because it’s so hard to break, and so easy to repair.

Any damage can be patched in situ, with no specialised equipment or hot works required.

HDPE’s combination of safety, durability and performance make the vessels perfect for tactical applications.

HDPE’s shock-absorbing, vibration-dampening properties mean the vessels can achieve maximum speed with minimal personnel fatigue, while compromising nothing in execution and handling.

From design to manufacture to end-of-life recycling, the Sentinel is a truly Australian vessel crafted for the highest level of strategic operations and emergency response – when failure is not an option.