If you can't read a book you can look at the pictures

The slate is for idiots. They also wrote this, aimed at those who still collect data by hand in the third millennium. And I collect data by hand, the old-fashioned way, because I'm good at it, because I enjoy it, and because I can be more precise than with electronic instruments. The difference is especially noticeable in the comments; the difference between a continuous string of numbers and more detailed information regarding the size of the cave, the type of seabed, and other details that reveal a lot to a careful reader; the difference between the data from a line and the data from a cave. But to collect data by hand, with a good level of precision, you need above all to be a skilled diver; obviously, for the lazy ones, the electronic instrument is more than enough.