The design behind the Legend: Why Rayglass boats are unsinkable

Last summer, on a quiet harbour in the North Island, our of our customers struck a reef  at speed on their Rayglass Legend 2500 and subsequently lodged a huge hole right on the bow.

Despite the massive force of the impact, his vessel kept floating and he motored home safely. When he got his boat to the trailer, he saw a gaping hole in the front of the hull and was shocked at how well his vessel had performed. 

This might seem like a remarkable story, but we weren’t surprised at all. 

The Rayglass Legend range of boats feature one of the most advanced and effective positive flotation systems in the world - and this boatie’s vessel did exactly what it was designed to do. 

Rayglass positive flotation system - best in the industry

Tony Hembrow, the mind behind Rayglass, considers the flotation system and hull integrity the number-one priority when designing a vessel:

“We build the entire boat around buoyancy. Right at the beginning of the design of any new vessel, we ask: ‘Where can we add positive buoyancy? Where does the foam need to go to ensure the boat can float no matter what happens to it?’”

The foam Tony’s referring to is RPF closed-cell endurathane, which is mixed at 1,000 psi and injected into all the hull’s cavities as a heated liquid. As it cools, it expands to fit the cavity and creates thousands of closed-cell air bubbles which add buoyancy. 

It’s not having the foam that matters - it’s where it goes

Rayglass pioneered the use of injected foam decades ago, and since then most other GRP boat manufacturers have followed our lead. But Tony says that claiming a vessel is ‘foam-filled’ is an easy statement to make - what really matters is where the foam is.

“If their hull is breached, most vessels will roll over leaving only the tip of the bow, stern or flipped hull above the water. If foam is injected unevenly throughout the hull, this will still occur no matter how much [foam] you pump into the hull,” Tony says. 

To prevent this from happening, Rayglass takes the unique approach of evenly distributing foam throughout the hull’s cavities, including up the sides of the vessel. This creates even buoyancy so that, even if you put a huge hole in the hull by running into a reef and the boat floods with water, your Rayglass boat will always get home safely. We believe that Rayglass is the only GPR boat maunfacturer in New Zealalnd to do this, making our design one of safest on the market.

 

The unsinkable Legend

Years ago, before great emphasis was placed on Occupational Health and Safety, Tony Hembrow and the Rayglass crew spent a month trying to sink every boat they built. They went out on the Hauraki Gulf and cut large holes into the hull of each vessel - completely flooding them - then loaded them with up to 15 people. 

The unique drainage system in the boats allowed water to drain in and out, making it impossible for them to fill to the top - despite all the weight and the extensive damage to the hull, every single boat floated upright above the water. 

They were trying their hardest to sink the things, but they just wouldn’t go down.

Tony says over the last 20 years or more, they’ve heard a few stories of this remarkable flotation system coming in handy:

“We’ve heard dozens of stories of people ripping holes in their hulls by running up on reefs, or hitting something in the water and coming home safe every time. The flotation system has been such a normal part of the Rayglass design for decades, we’ve sort of forgotten how remarkable it is that they’re just about unsinkable.”