Dive tables are to many divers one of the most challenging and complicated to master. The growing tendency for training agencies to move away from traditional dive tables in favor of dive computers has let a growing void in diver education. While the use of dive tables is still common practice in the technical diving arena, recreational divers often never pick up a set of tables after their initial open water diver class due to the use of personal dive computers.
Understanding dive tables is fundamental. It is analogous to having a calculator fail and not knowing how to personally perform arithmetic.
Though computers are the trend, we should not forget the fundamentals that lead us to where we are today.
Image you just spent $8000 to travel half way around the world. You are on a dive and your computer fails. You did not carry a backup computer and there are none available on the boat. Presuming you have a watch and a depth/pressure gauge you could continue to dive. You’ll just have to rely on the tables to tell you your bottom time for a given max depth.
I strongly urge you to study dive tables. They really are not hard to learn. With a little practice and repetition, your comfort and knowledge will grow. Before you know it, you will be echoing out numbers with authority.