basic info
Dive # - Whether you've done 2 or 200 dives, it's always nice to know what number you're up to! Most people count their 1st ever dive either as their Discover Scuba Diving or Try Dive experience, or as the 1st dive on their Open Water Course. PADI defines an open water dive as the following:
"During open water dives, have divers spend the majority of time at 5 metres/15 feet or greater, and breathe at least 1400 litres or 50 cubic feet of compressed gas or remain submerged for at least 20 minutes"
So while pool or confined water dives don't "count" - there's no harm in dedicating a page to them if you feel it would be useful for you to look back on, but maybe don't increase your total dive tally.
Date - The date when you completed the dive
Location - The geographic location where you dived e.g. Plymouth, England; Bali, Indonesia; Key Largo, Florida
Dive Site - A more detailed description of the location of the dive site, all popular sites will have their own unique name or the name of the wreck. E.g. The Thistlegorm, Great Blue Hole, Barracuda Point
World Map - Mark off where you are in the world.
Dive Statistics
Time In - The time that you entered the water and started your dive, your dive computer will record this.
Bottom Time - The total time you spent underwater (including any safety spots), this will be recorded on your dive computer.
Time Out - The time you finished your dive. Not all computers display this, but you can work it out by adding you total bottom time onto the time you entered the water. E.g Time in 10.02am, Bottom time - 42 minutes, Time out - 10.44am
Total Time - This is the total amount of time you've ever spent underwater! If this is your first dive, this number will be the same as your bottom time. For all subsequent dives you should look back at the dive before and add the newest dive's bottom time on. E.g.
Dive 1 - Bottom time 42 mins - Total time - 42 mins
Dive 2 - Bottom time 40 mins - Total time - 82 mins (1hr 22mins)
Dive 3 - Bottom time 45 mins - Total time - 127 mins (2hrs 7 mins)
Visibility - How far you can see underwater, this is just a guess and is subject to interpretation, you can discuss it with your buddy afterwards. If you can barely see your hand in front of your face, you might record the vis as <1m. If you can see a little bit ahead of you, it might be between 3-10m. If it's like being in a swimming pool, then it'll be around 30m+
Air In - When you've set up your gear and you're doing your pre-dive safety checks, you should check your regulators and your air gauge. Before a dive your tank should be full, and most fills are somewhere between 190-230bar. Try to remember how much air you started with so you can record it here after your dive.
Air Out - The air left in your cylinder when you've finished your dive. Most dives should be ending when you have around 50bar left, however as you improve your air consumption will get better and it'll be nice to see some progression if you record the air pressure you finish with.
EANx% - This stands for Enriched Air Nitrox % and is a measure of how much Oxygen is in your fill. If you are diving on air, as is standard, then this will be 21%. If you take a Nitrox course and dive on nitrox, most fills are 32% although this will change due to the nature of the dive and varies a little bit from fill to fill as it's not a precise art. Before a nitrox dive you should analyse the contents of your tank and record this on a sticker on the outside, it may be +/-1.5% from what you asked for.
Max Depth - The maximum depth you reached during the dive, this will be recorded on your dive computer.
Avg Depth - The average depth you were at throughout the course of the dive. This should also be recorded on your dive computer.
Current - This is subjective to you, if you feel there was very little current, you may fill in 1 circle. If, to you, you felt the current was really strong (or maybe you were doing a drift dive), you might fill in 4 or 5 circles.
Waves - Another subjective measurement, whether you were diving from shore or from a boat, if you felt there was very little surf / swell, or loads, you can fill in as many circles as you see fit.
equipment
Water Temp - The temperature of the water, your dive computer should tell you this.
Suit - Were you wearing a 3mm shorty? A 5mm full length wetsuit? A semi-dry? Or a dry suit?
Hot / Cold / Ideal - Based on what you were wearing, how comfortable were you temperature wise? Where you too hot or too cold? Or were you just right? This is really important information to look back on to make sure you can plan the appropriate thermal protection for the water temperature.
Fresh / Salt - Whether you were diving in fresh water or salt water
Tank - There are lots of different types and sizes of tanks or cylinders. They are either made from Steel or Aluminium. If you're diving in Asia, you're more likely to be using an Ali80 (Aluminium tank, 80 cubic foot, 11.1 litres), if you're diving in the UK, you're like to be either using a 10L or 12L steel tank. If you're renting a cylinder and not sure, just ask your dive centre.
Weight - How many kilograms of lead did you use?
Over / Under / Ideal - Based on whether you were in fresh or salt water, the type of tank you were using and the amount of weight you had on, did you feel over weighted or under weighted? Buoyancy is linked to all these factors (plus what suit you're wearing) so it really is important to note down as will help you adjust your weighting accordingly in future. Plus, it serves as a handy reminder for those holiday dives!
comments and sign offs
Training Dive - If this dive happened to be as part of a course, you can record it here. Maybe it was Open Water Dive 3, maybe it was part of a specialty course. If you're not sure what to put, ask your instructor.
Comments - This is your dive log and is your personal diving journal. Lots of people like to write memorable points from the dives (Saw a turtle!), some make diagrams of the route they followed. Others write notes to remember for next time based on their professional's feedback.
Buddy / Pro - If you were diving with a buddy, they can sign the dive off (it's also nice to look back and see who you did what with!), or if you were diving with a Dive Master or Instructor, they can sign off the dive with their name and Pro number. It's important to get dives signed off as if you take further courses you may be asked for evidence of your previous dives.
Stamp - All dive centres will have their own customised stamp that they can put here to confirm the dive.