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Dive Table Overview


Please note that due to differing display screen resolutions and also color depths, no everyone will see the data equally clearly. normally recommends that each diver very own a an individual copy of the tables.

The Dive Tables usage a Letter team designation come express the quantity of residual nitrogen in your body. The letters variety in sequence from A come L. The letter A represents a little amount of nitrogen and the amount of nitrogen increases as the letters development towards L. Once you dive, a Letter team from the tables designates the amount of nitrogen girlfriend have took in during the dive. As you spend time on the surface in between dives, you are assigned to “lower” Letter teams as friend offgas nitrogen.

When you start a dive again come a offered depth, her Letter team at the time determines the time representing the residual nitrogen in your body. The tables display you how to subtract this time from the common dive time limits, which outcomes in a much shorter time limit for your repeated dive. Girlfriend must add your residual nitrogen time to the time you actually spent diving to recognize your total nitrogen time at the end of the dive. You usage the total time to identify a brand-new end-of-dive Letter Group. The dive time calculator is based on the dive tables, yet it eliminates the calculations compelled to identify Letter teams when girlfriend make an ext than one dive. The dive time calculator additionally reduces the errors that are often made once reading dive tables. It is basic to learn just how to use a dive time calculator, but you must do this only after you are acquainted with the measures for planning dive time limits using the dive tables. A dive time calculator might not constantly be available, yet dive tables usually space (figure 5-4).

A selection of dive tables, dive time calculators, and also dive computer systems exist. The info they provide varies and some are an ext conservative 보다 others. Numbers and also Letter teams are not constantly interchangeable between tables. Always use the kind of table, calculator, or computer system with i beg your pardon you are familiar. If her dive friend is making use of a various type, you need to agree to usage the many conservative dive to plan information.

Dive Table Organization

The Dive Tables room composed of 3 tables:

Table 1 – End-Of-Dive Letter GroupTable 2 – surface ar Interval Time (SIT) TableTable 3 – repeated Dive Timetable

The Dive Tables are based upon the us Navy Decompression Tables and also have to be designed especially for entertain diving (figure 5-6). The tables are designed to circulation from one to the various other in a constant loop (figure 5-7).

When you are using the tables, be certain to use a ruler or a straight-edged thing to review the numbers across and job-related your means from table to table. If you shot using a finger to map your course through the tables, you might slide into another row and also read the table incorrectly, particularly if you space on a rocking boat.


Dive Table Terms

Different dive tables and also dive computers might use terms different from the ones provided in the Dive Tables (figure 5-5). Also, the very same term could have a various meaning.

The following terms use to the Dive Tables:

Dive ScheduleThis is an abbreviated statement providing the depth and time of the dive. It is expressed as depth/time (for example, 21 meters/40 minute or 70 feet/40 minutes). The is likewise called a dive profile, particularly when the is one dive in a sequence of dives.Maximum Dive Time (MDT)This is the time you can spend at a given depth without having actually to do a required decompression stop during ascent. This time is additionally known as the preferably Allowable Dive Time or no-decompression ddmit.Decompression StopThis is a suggest in a dive wherein you prevent at a stated depth because that a mentioned time during climb to enable nitrogen offgassing before continuing your ascent or surfacing.Precautionary Decompression StopThis is a protect against at five meters (15 feet) for 3 minutes together a safety precaution as soon as you have not gone beyond the maximum Dive Time. You have to perform such a stop at the finish of every dive. It is additionally known as a safety Stop.Required Decompression StopThis is the lot of time stated by the Dive Tables, the you have to spend at five meters (15 feet) whenever friend exceed the best Dive Time. Various other tables specify extr stop depth for depths or longer dives.Actual Dive Time (ADT)This is the elapsed time from the minute you start your descent from the surface until the time you go back to the surface. Time invested at your Safety avoid does not have to be had in the yes, really Dive Time when determining her Letter Group.Residual NitrogenThis is the excess nitrogen staying in your body from any dive or dives made before you have fully offgassed.Letter group DesignationThis letter symbol identify the lot of residual nitrogen you have in your system. The closer the letter is come the start of the alphabet, the less residual nitrogen you have in your body.Surface term Time (SIT)This is the time spent on the surface in between dives. During this time, your body is eddminating overabundance nitrogen. Your Letter group will change and move closer come the beginning of the alphabet, depending on how lengthy you space on the surface.Repetitive DiveThis is any kind of dive the you make prior to you have totally offgassed from any previous dive or dives.Residual Nitrogen Time (RNT)This is the lot of time you must consider as currently having been spent at a given depth because that a planned recurring dive. This time is based on the residual nitrogen staying in her body native a ahead dive or dives.Adjusted preferably Dive Time (AMDT)This is the best Dive Time minus the Residual Nitrogen Time because that a repetitive dive come a provided depth.Total Nitrogen Time (TNT)This is the amount of your Residual Nitrogen Time and your actual Dive Time adhering to a repeated dive. You usage this full to obtain your brand-new Letter group at the finish of the dive.

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Dive Table Rules

You must recognize the adhering to Dive Table rules completely. Similar rules will apply to any new set of dive tables or dive computer that you can use to calculate your dive times.

Ascend no much faster than 9 meters (30 feet) every minute. This is 0.3 meter (1 foot) every 2 seconds. You need a timing an equipment and a depth gauge (or a dive computer) to measure up your price of ascent. This rate will seem fairly slow come you.Use the exact or the next higher number detailed in the table for her depth. If girlfriend exceed a number in the table, use the next higher number. The depth in the table variety from 12 meters (40 feet) come 40 meter (130 feet) and also increase in increments of 3 meters (10 feet). Because that example, you round a dive to 13 meter (43 feet) as much as a 15 meter (50 foot) dive.Use the precise or the next higher number detailed in the table for her time. If you exceed a number in the table, use the next better number. The times selection from 5 minute to 130 minutes. For example, you ring a dive come 15 meter (50 feet) because that 41 minutes approximately 50 minutes.Use the deepest depth girlfriend reached during your dive to identify the dive schedule for her dive. Because that example, if you perform a dive come 18 meters (60 feet), however spend most of the moment at 12 meter (40 feet), girlfriend must think about the dive to it is in an 18 meter (60 foot) dive.Always make your deepest dive first when make a collection of dives. Setup each that your recurring dives to a shallower depth 보다 your vault dive. This might permit you come offgas nitrogen on progressively shallower dives and also prevents you from carrying increasingly larger quantity of residual nitrogen top top deeper recurring dives.Consider any kind of dive shallower than 12 meter (40 feet) to be a 12-meter (40-foot) dive when planning your dives.Surface interval Time (SIT) need to be at least 10 minutes in between dives. If your SIT is much less than 10 minutes, girlfriend must consider your 2nd dive together a continuation of the first dive. recommends a SIT the at the very least one hour between dives.Use the next higher dive time if your dive is an especially cold or strenuous. Because that example, if you do a dive come 18 meters (60 feet) because that 22 minutes, the 22 minutes rounds to 25 minutes. However, if you end up being chilled throughout the dive, round the time again come 30 minutes.Avoid dives the take you best to the no-decompression border for any given depth and also time combination. If girlfriend accidentally overstay your bottom time or usage an incorrect ascent rate on such a dive, you can be in a forced decompression situation or endure DCS. Always allow yourself enough time to do a slow, comfortable ascent with lot of of air.