Having unlimited writing or for that matter, sketching ability when diving can really make documenting your experiences, students evaluations, reef or marine life identification, dive log data, repetitive dive data etc a breeze and detailed. Anything that can be done on land with paper can now be done underwater... Draw, write, erase, save, scan, copy, print, etc. Your Aqua SketchMinno will eventually run out of paper so here is a supply that will last a long time. Package contains four rolls for lots of writing.