We had tested these materials last week. Some were impervious to water whilst others proved useful, due to their size, and could be made impermeable using water-repellent materials.

Freddie designed this watertight container for jewelry by using two fruit shoot bottles slotted together.

Josh decided that due to the ferocity of a tsunami his container would need to be lockable. He hoped that this would protect his family photos from escaping the box!

Envy experimented with aluminium as an impermeable material. She also chose this as it reflects light well and could therefore be easily found amongst the debris.

Quite a few children used the colourful packets, that once contained crisps. Colourful, water repellent and malleable meant they were the ideal material.