Maybe I'm old school. or maybe I'm just old, but I think there is more to a log book than the other responders here, and I recommend you keep a paper dive log book even if you have a digital one. First, the only certifications requiring you to present proof of a given number of dives are professional certifications- divemaster, instructor. However, some dive concessionaires will want to see a certain number of logged dives for you to participate on certain dives- especially some wreck dives. A second reason is that I write a lot more information in my log book than the digital download from a computer offers, including topographic features, things and creatures seen, current and wave and wind conditions, what exposure gear I was wearing, how I was weighted, and so on. electrical one. This is really useful as I dive in a variety of venues and conditions, from high altitude cold water to 85 degree seas, and my log book is a reference for me (and others who ask) as to what is proper exposure gear and weighting. Also, I note changes in conditions at time of day and time of year, and can through time accumulate a lot of information on when to dive a site for finding whatever I am after. I also am very much in favor of having someone sign every dive as confirmation it occurred.
Finally, I have new friends put contact information my log. The net result is a great read, at least for me, between dive outings. We are headed soon to a place in Mexico to dive where we have been before. I am reading every logged dive in that area, so we can plan sites we want to do, avoid the ones that were not as cool, and take proper gear/equipment. ( I also log what I had with me I didn't need and what I wish I had that I didn't take.) My log book presents my underwater history, including number of dives (each one verified), total time under the water (a more significant number in my opinion), and lots of interesting notes to call to mind wonderful memories and help plan for making new memories. I have several volumes on the shelf in the scuba room at home, and keep only about the last 100 dives in my "traveling log book." I encourage you to start and always continue, a meaningful log book.
DivemasterDennis
Finally, I have new friends put contact information my log. The net result is a great read, at least for me, between dive outings. We are headed soon to a place in Mexico to dive where we have been before. I am reading every logged dive in that area, so we can plan sites we want to do, avoid the ones that were not as cool, and take proper gear/equipment. ( I also log what I had with me I didn't need and what I wish I had that I didn't take.) My log book presents my underwater history, including number of dives (each one verified), total time under the water (a more significant number in my opinion), and lots of interesting notes to call to mind wonderful memories and help plan for making new memories. I have several volumes on the shelf in the scuba room at home, and keep only about the last 100 dives in my "traveling log book." I encourage you to start and always continue, a meaningful log book.
DivemasterDennis