Updated: 8 Nov, 2017
Many people are surprised that I still log my dives, in full, every time, by hand into a log book. I get asked “why”, or more bluntly “why bother?” frequently.
Before I answer my reasons, I want to list all of the reasons I can think of to log dives – in detail or otherwise.
Weights and wetsuits
One of the questions a dive shop will ask a diver when renting out gear is “how many weights do you need?” and “what kind of wetsuit would you like to wear?”
Do you remember how many weights you used last time? Were you using a 3mm shortie wetsuit? 5mm semi-dry? Knowing your required weight in the past gives you a good start for how much weight you need for the new location, without having to go through weight checks, or to avoid starting off grossly overweighted.
Different water temperatures and salt content in the water can affect weight and exposure suit choices, but knowing your past uses speeds up the process dramatically.
This is one of the first reasons I put forward to new divers to keep logging dives.
To be allowed to dive
Some countries (like Israel) require that you show proof of a logged dive within the last 6 months, otherwise you are required to take a refresher. This is beyond the normal PADI recommendation, and is a legal requirement.
So, if you’re planning a diving trip there, and are going on a boat (like a liveboard), you might not be able to dive at all, if you’re in a place where they can’t run a refresher course. So, don’t just log every dive – bring your log book with you!
If you have 50+ logged dives, then you can go up to 12 months of inactivity before a refresher is required. For Master Scuba Divers, or Divemasters (any dive professional), the requirement is waived.
A good debriefing and log book session is a great time to chat with your fellow divers. Get to know them, get advice about the dive and your diving, and tips for future dive travel.
Make use of this time to enjoy a rehydrating drink, to help prepare you for the next dive (if logging between multiple dives in a day).
Certain dive sites
Some dive sites are considered rather difficult to dive. For example, there is one in the south of Lombok, Indonesia, called “The Cathedral”, which is a pair of pinnacles in high current, with a peak about 15m-20m down.
One dive shop will take you only if you’re a Divemaster or higher.
The other will take you if you’re not, but you need to be at least Advanced Open Water with 100 logged dives.
Log books can make a nice memento of a dive shop you went diving with. They can be nice conversation starters among divers too.
Going over the fish and life you saw can help cement common names in your memory. Grab the identification books in your dive shop to go over with your Divemaster as you log your dive. Soon you’ll be recognising fish like an expert!
As a backup in case of computer failure
If you log everything, including surface intervals, then if your computer fails, you can switch to tables (using the PADI eRDPML for example) and potentially continue diving, with a clock and depth gauge, after calculating your pressure group.
Log books can be used as a way of tracking your personal achievements, such as total time underwater, average or maximum dive length, deepest dives and so forth. This can lead to personal improvement, and encourage increased physical fitness.
A good role model
An Instructor or Divemaster logging their dives is a good role model to guests, to help encourage them to log their dives.
Just get excited about diving!
Having a good debriefing and log book session is a great way to relive the dive! It’s a social bonding moment for the divers, getting to talk about their favourite parts of the dive.
Some people like to draw things they’ve seen. Some sketch site maps. Some make broad notes. Some list every species they saw. Some people have a check list of animals they want to see, and mark them off, one by one.
Dives can start to blur together after a while, and going through a log book session with your Divemaster is a great way to sort and solidify an individual dive in your mind.
Ultimately, it’s a way to get excited about the dive you just had, and to build anticipation for the next dive you will have.