This sturdy plastic slate for recording information underwater.
It has a clip to attach to your BCD and a pencil that is securely attached so it doesn't float away. Measuring 150mm x 125mm, it is designed to fits easily in a pocket when not in use. The slate is printed with a scale and a checklist of things to record.
Carry one with you on every dive.
Each slate also includes a Seasearch "waterproof" pencil made from recycled DVD cases.