Understanding Dive tables
Scuba Dive Tables
Dive Tables – Dive With SSI there are three dive tables to calculate single and repetitive air dives.
Dive Table One: Dive Table one allows you to pre-plan your maximum depth and time limit for first or single dives, and is also the Dive table you use AT THE END OF EVERY DIVE to determine what ‘Group Designation Letter’ you are. Go to example
What is a Group Designation Letter’: As a means of considering the quantity of residual nitrogen in a person after scuba diving, we assign ourselves a letter. After a scuba dive, a diver might be called a ‘G Diver’.
Dive Table Two: Dive Table Two is known commonly as the ‘Surface Interval Table’. It is used for repetitive dives to work out what Group Designation Letter you are at the BEGINNING of each new repetitive dive. Go to scuba dive example
What is a repetitive dive?’ A repetitive dive is any dive started more than 10 minutes and less than 12 hours after a previous scuba dive. If you begin a dive within 10 minutes after your last dive, it’s considered as the same dive. As long as you have remained within your limits, if you have over 12 hours in between dives it is considered a new diving day.
What is a Surface Interval?’ A Surface Interval is the amount of time you spend on the surface or out of the water in-between scuba dives.
Dive Table Three: Dive Table three is commonly known as the ‘residual nitrogen table’. At the beginning of each repetitive dive we still have residual nitrogen remaining in our bodies from previous scuba dives, which needs to be accounted for. The way we account for this nitrogen is by pretending that we have been underwater for longer than we really have. Dive Table three tells us how much additional time we have to add on for each repetitive dive.
Dive Table three also allows us to pre-plan our maximum time and depth limits for repetitive dives, to ensure we stay within the limits. Go to example