Acrylic boards This material is suitable for annotations under wet conditions, including underwater. Large acrylic plates (1.2 mx 1.8 m) were cut into smaller sections with a sharp cutter. Depending on the requirements for their use, the boards were cut into different sizes; for annotation at the surface, 30cm x 22cm sections were prepared, while for underwater work smaller 22cm x 15cm boards were prepared, to make them more ergonomic and to optimize use of space. Sandpaper was used to scrape the surface of the boards and make them abrasive enough to write on with an ordinary graphite pencil. Small holes were drilled close to one of the corners, to insert steel rings for facilitating attachment to the D-rings on the harness/BCD (buoyancy control device), using double-ended bolt snap hooks. When underwater, pencils are easily lost or broken. To avoid this, use of latex tubes and small cable ties is recommended for securing pencils and keeping them safe when not in use (Fig. 2).