How to Use Dive Tables Like a Pro (With Free Printable Dive Charts!)

How to Use Dive Tables Like a Pro (With Free Printable Dive Charts!)

Dive computers are fantastic, but every diver should understand how to use dive tables. They're a fundamental skill, a crucial backup in case of computer failure, and provide a deeper understanding of dive physiology. This guide will break down how to use dive tables like a pro, and we'll even provide free printable dive charts!

Why Learn Dive Tables?

• Backup: Computers can fail. Knowing how to use tables is a vital safety net.

• Understanding: Tables teach you the principles of nitrogen loading and decompression, improving your overall dive knowledge.

• Skill Enhancement: Mastering tables makes you a more self-reliant and informed diver.

Understanding the Basics:

Dive tables are designed to help you calculate your safe diving limits, preventing decompression sickness (DCS). They work by tracking the buildup of nitrogen in your body at different depths and times.

Key Terms:

• Depth: The maximum depth reached during your dive.

• Bottom Time: The time spent at depth, from the moment you begin your descent until you begin your ascent.

• Residual Nitrogen Time (RNT): The amount of nitrogen remaining in your body from previous dives.

• Surface Interval: The time spent on the surface between dives, allowing your body to off-gas nitrogen.

• Repetitive Dive: Any dive taken after a previous dive, before the nitrogen has fully dissipated.

Using the PADI Dive Tables (Most Common Example):

We'll use the PADI tables as an example (other table systems exist, but the principles are similar).  It is highly recommended to take a course or training with a certified instructor to learn dive table use correctly.

1. Determining Your Pressure Group After a Dive:

• Find your maximum depth and bottom time on Table 1.

• Locate the corresponding pressure group letter. This letter represents the amount of nitrogen absorbed during the dive.

2. Calculating Residual Nitrogen Time (RNT) for a Repetitive Dive:

• Find your pressure group from the previous dive.

• Go to Table 2 and find your surface interval time.

• Locate the new pressure group letter corresponding to your surface interval.

• Go to Table 3 and find your new depth for the repetitive dive.

• Locate the RNT value associated with your previous pressure group and the new depth.

3. Calculating Actual Bottom Time for a Repetitive Dive:

• Use Table 3 to find the maximum allowable bottom time for your planned repetitive dive depth.

• Subtract your calculated RNT from this maximum allowable bottom time. The result is your actual allowable bottom time for the repetitive dive.

4. Ascent Rate:

• The PADI tables recommend a maximum ascent rate of 60 feet per minute. Your dive computer also tracks this.

Free Printable Dive Charts:

[Link to your free printable dive charts here. You can create these yourself in a word processor or spreadsheet or find them online. Make sure they are accurate and match the table system you're describing.]

Example Scenario:

Let's say you made a dive to 60 feet for 30 minutes.

1. You'd find your pressure group on Table 1 (likely "E").

2. After a 2-hour surface interval, you'd use Table 2 to find your new pressure group (likely something like "D").

3. If your next dive is to 40 feet, you'd use Table 3 to find your RNT and calculate your allowable bottom time.

Important Considerations:

• Always consult the official dive table instructions: This guide provides a simplified overview. Refer to the official PADI (or whichever organization's) dive tables for complete and accurate instructions.

• Practice, practice, practice: Practice using dive tables regularly to become proficient.

• Take a course: A dive table course from a certified instructor is the best way to learn how to use them correctly.

• Dive computers are recommended: While knowing tables is crucial, dive computers are highly recommended for their enhanced safety features.

• Safety First: Always dive within your limits and follow safe diving practices.

Beyond the Basics:

Advanced dive table use includes topics like:

• Altitude diving: Adjustments for diving at higher elevations.

• Multi-level diving: Planning dives with varying depths.

Conclusion:

Mastering dive tables is a fundamental skill that enhances your diving knowledge and safety. Download our free printable dive charts, practice regularly, and consider taking a course to become a true dive table pro! Remember, dive tables are a backup – always dive with a reliable dive computer if possible. And most importantly, dive safely!