"Let's put carbon fibre in there," says the marketing director. "That stuff's stronger. And I can sell it as a high-end feature."

"Yup, yup," replies the shop foreman. "We can do that. It's a bit pricey though, maybe we could use just a bit of it mixed with the fibreglass."

Fast forward three years, and both men are scratching their heads over why the component- which was, according to the designer, more than strong enough in fibreglass alone- has failed catastrophically even though they added a "better" material.

TL;DR: Mixing different fibres in the same load path can lead to a component being weaker than it would be if only one type of fibre had been used.

Improperly mounted hardware is a constant source of frustration for boat owners. Sometimes it's water leaking in through a bolt hole, sometimes it's rust bleeding onto the deck, sometimes it's a cleat that tears off its mount under load.

Here's how to mount hardware on cored fibreglass decks correctly, so you won't have to deal with it again- and a few examples of why things go wrong otherwise.