Dive Log

THE DIVE LOG

The scuba diving log book is a very valuable document. It should be treated as a diary of diving activities. It provides the following beneficial information:

You have forgotten the weight you need with your 3/2 mm wet suit in the ocean. Since you dove there previously you need only to refer to the log book to tell the Divemaster how much weight you need.
You are returning to your favorite quarry in April and wish to know what the water temperature will be and what suit you should wear. Check the log for last April's dives in the same quarry.
Your underwater camera developed a leak. You want to return it to the manufacturing company. Check your log to see how many dives you had with the camera so you may determine whether it is a manufacturing defect.
What was the visibility in New Jersey when you dove there 3 years ago at the same time of the year? Check the log!
Is the emergency number for DAN in the log book?
You develop a serious medical condition some hours after a dive. Is the log book part of the search for the cause? It should be!
How many different Caribbean islands have you been to? How many times have you been to Grand Cayman?
What did you see on a dive? When did you see the Loggerhead? How deep were you when you observed the Water Snake in Minnewaska? Your log should tell you.
You need to prove you have had 60 dives to exit from the PADI Divemaster course. Where else would you be able to get that information?
The dive boat has a form that requests the number of dives you have had. It also requests you to list the date of the last dive. The captain is going to use those forms to determine the skill level of the dives for the day. Grab that log book!
When did you make your 100th dive?

Log every dive. Fill in all the data requested. It will be to your great advantage!

The following is one page from the Deep-Six dive logbook. Each of the entries is explained following the picture.

Dive Number: Sequential starting with your 1st open-water dive during your certification course
Location: Such as Lake Mohonk, or West Palm Beach on the wreck, Princess Ann, etc.
Date: The date the dive was done
Dive Buddy: One or more people that have committed to be with you during the dive.
# is the total number of divers that were on the dive
Temp (Sur/Btm); The recorded temperature found at the surface and at the deepest depth.
Visibility: How far you can see horizontally during the dive (it may vary)
Suit/Wts: The physical description of the suit you wore (size, thickness, etc.) and the amount of weight needed.
Notes: Here you should record any experiences, observations, new equipment, training, etc.
SI: This is your surface time spent degassing between dives (hours:minutes)
Rep Grp: The new Repetitive Group (A-Z) after degassing between dives.
Tank Pressure Start: Using the Submersible Pressure Gauge (SPG), read the tank pressure before entering the water. Record that number here.
Tank Pressure End: Using the Submersible Pressure Gauge (SPG), read the tank pressure after leaving the water and then record that number here.
Total Hrs To Date: The number of hours spent in the water - The number comes from the previous logged dive.
Hours this Dive: The number of hours and minutes from the time of entering the water to the time of exit.
Total Water Hours: Add the Hrs to Date and Hrs this Dive and put the total here. Also that number goes on the next log page under Hrs to Date. The time accumulates for your entire diving career
Start: Put the time you entered the water before and after the colon, such as 13:23. Use Universal Time
End: Put the time before and after the colon, such as 17:05, for when you leave the water. Use Universal Time
Depth Max: The maximum depth you reached (from the computer, or Maximum Depth Indicator on the depth gauge)
Bottom: From the time you submerged until surfacing. Surface time does not count. Read this number from the computer or watch. It's in minutes.
RNT: (Residual Nitrogen Time) If you had a previous dive, put the RNT here. This has to be figured from the decompression table.
ADT: (Actual Dive Time) This, again, is the bottom time.
TDT: (Total Dive Time) Add the RNT and the ADT and put that total here.
Letter Group: Use the TDT and the maximum depth to figure your ending Repetitive Group from the decompression table. Put that letter in this box

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