Every diver should keep a log. Not only is it a great way to keep track of memories and stuff like that, and cool places you’ve dove, but it’s a record of all of the different places you’ve been. It counts for many resorts, what to see, how many dives you’ve done, and what kinds of dives you’ve done before they’ll let you dive with them.
A dive log such as this one can also be a great place to store your certification cards. So, if you start collecting too many to fit in your wallet, put them in your dive log..
As found on Youtube