Plunge Limits: How Deep Can You Dive Without Decompression?

If you’re wondering ‘how deep can you dive without decompression,’ the answer lies in understanding No-Decompression Limits (NDL).

This introductory guide dives straight into how NDLs govern the depth and duration of your dives before decompression stops become a necessity.

With safety and efficiency being the primary focus, we’ll discuss;

  • the roles of dive tables and computers
  • the science behind decompression sickness, and
  • tips for staying within safe diving parameters.

Key Takeaways

  • No-Decompression Diving is central when it comes to safe scuba diving. No Decompression Limits (NDLs) indicate the maximum time divers can stay underwater at specific depths without decompression stops to avoid decompression illness.
  • Decompression Sickness (DCS) is caused by nitrogen bubbles forming in the body due to pressure changes; recognizing symptoms such as joint pain and tingling in extremities is essential for timely treatment.
  • Most divers use dive computers to help stay within NDLs; these tools dictate ascent speed and alert divers before reaching NDLs to prevent DCS.

Understanding No-Decompression Diving

Scuba divers exploring a colorful coral reef underwater

No-decompression diving significantly contributes to a scuba diver’s safety underwater.

It refers to the ability of a diver to ascend to the surface at any time during the dive without the necessity of making decompression stops.

It is governed by the No-Decompression Limit (NDL), which refers to the maximum allowable time for a scuba diver to stay at a specific depth without the need for decompression stops to prevent decompression illness.

For scuba divers, sticking to these limits during a scuba dive is a priority to ensure safety and avoid mandatory decompression stops, making scuba diving a more enjoyable experience.

What is No Decompression Limit (NDL)?

The No Decompression Limit (NDL) plays a pivotal role in ensuring safe diving practices.

Staying within the NDL is vital to prevent decompression illness and guarantee a safe surfacing for divers. The NDL is determined through the use of dive tables and dive computers, which consider the body’s absorption and tolerance of nitrogen at different depths.

However, if a diver exceeds the NDL, it becomes necessary to execute decompression stops to facilitate a safe decompression process prior to surfacing.

Factors Affecting NDL

A diver’s NDL is subject to several influencing factors during a dive, such as depth, time, and residual nitrogen.

As the diver descends deeper and spends more time underwater, their available time before decompression decreases, making it more challenging to dive deeper without the need for decompression stops.

Residual nitrogen, the elevated pressure of nitrogen left in a diver’s body after a dive, can affect future dives by shortening the permissible no decompression times.

Hence, managing this trapped nitrogen is fundamental to prevent decompression sickness and ascertain the maximum depth you can dive without experiencing decompression issues.

The Science Behind Decompression Sickness

hyperbaric oxygen therapy chamber

Decompression sickness, a potential risk for all divers, occurs when nitrogen absorbed in the body forms gas bubbles that can become trapped within the system, a result of pressure changes experienced by divers at depth.

Therefore, understanding the science behind decompression sickness, including the process of nitrogen absorption and release in the body, is critical for all divers.

Nitrogen Absorption and Release

As a diver descends deeper underwater during a dive, the body absorbs nitrogen from the air tank due to the increased pressure.

As the diver ascends, the absorbed nitrogen is transported in the blood to the lungs, where it is exhaled. A gradual ascent back to the surface is recommended as it facilitates the safe release of nitrogen from the body as pressure decreases, thereby preventing the formation of potentially harmful nitrogen bubbles.

Poor management of these bubbles could lead to decompression sickness.

Signs and Symptoms of Decompression Sickness

Recognizing the signs and symptoms of decompression sickness is crucial for timely intervention. Symptoms encompass a spectrum, including:

  • Tingling in the extremities
  • Joint pain
  • Fatigue
  • Cloudy thinking
  • Numbness
  • Weakness

In severe cases, decompression sickness can lead to fatality. It is important to seek medical attention if you experience any of these symptoms after diving.

Therefore, divers must be mindful of these symptoms as they can be easily misidentified as those of other medical conditions.

Dive Tables and Computers: Tools for Safe Diving

divers putting on their dive computer

Now, we will examine the tools that assist divers in tracking their dives and maintaining safety.

Using Dive Tables

Dive tables, on the other hand, offer predetermined data such as the maximum dive time at a given depth, the required surface interval between dives, and the no-decompression limit for a specific dive profile.

This information assists divers in planning safe dives by providing essential parameters.

The no-decompression limit (NDL) in a dive table signifies the utmost duration a diver can stay at a specific depth without necessitating decompression stops. The components of a dive table include the residual nitrogen table and other safety data charts.

The significance of conducting a safety stop during a dive is to enable the gradual release of pressure and nitrogen absorbed by the body during the dive.

Dive Computers

Dive computers and dive tables play a crucial role in preventing decompression sickness by:

  • Monitoring the real-time accumulation of nitrogen in the body
  • Adjusting the ascent speed accordingly
  • Helping divers to monitor their NDL (No Decompression Limit) during a dive
  • Alerting them before they reach their NDL

Hence, divers should strictly adhere to the ascent speed dictated by the dive computer.

Dive computers offer essential data, including depth and no-decompression limits, in a digital format, akin to conventional dive tables.

To accurately interpret this data, it is crucial for a diver to utilize a dive computer with a sizable and clear display and comprehend the manner in which the computer conveys its information.

Dive computers offer a range of functionalities to ensure the diver is aware of critical dive parameters at all times. These include:

  • Depth
  • Time
  • No stop time remaining (indicative of no-decompression limits)
  • Ascent rate
  • Emergency decompression
  • Previous dive information
  • Low battery warning

Dive computers utilize intricate algorithms based on the Haldane equation to automatically calculate the no-decompression limits, considering the gas loading in tissues during a constant-depth dive. They facilitate real-time monitoring to enhance diver safety.

Safety Stops vs. Decompression Stops

diver performing a safety stop

Both play crucial roles in ensuring the safety of divers during their underwater adventures.

A mandatory decompression stop is necessary when the level of nitrogen dissolved in the body surpasses a specific threshold, requiring a period for nitrogen to off-gas safely.

On the other hand, a safety stop is a preventative measure advised after deeper dives to facilitate gradual release of any excess nitrogen, even if no mandatory decompression limit has been surpassed.

The significance of conducting a safety stop during a dive is to enable the gradual release of pressure and nitrogen absorbed by the body during the dive.

Performing a Safety Stop

Performing a safety stop is an important aspect of diver safety.

It allows divers to give their bodies extra time to release any remaining nitrogen, reducing the likelihood of decompression sickness and eliminating the necessity for decompression stops.

The recommended depth for a safety stop in diving is 15-20 feet (5-6 meters), and divers are advised to remain at this depth for at least three to five minutes.

Neglecting to perform a safety stop during a dive can elevate the likelihood of experiencing a decompression incident and potentially developing decompression sickness.

It’s important for divers to be aware of common mistakes/risks during a safety stop, such as neglecting personal fitness, running out of air, wearing too much or not enough lead, and more.

Mandatory Decompression Stops

On the other hand, mandatory decompression stops become necessary when divers surpass their no-decompression limits (NDL).

In such instances, they are required to execute these stops at designated depths for specified durations as instructed by their dive computer or decompression tables.

The specific duration of the decompression stop may be influenced by the depth and duration of the dive, as well as by specific guidance from your dive computer/dive tables.

Neglecting mandatory decompression stops significantly elevates the likelihood of nitrogen bubbles developing in the diver’s body, potentially resulting in decompression sickness (DCS).

Tips for Diving Without Decompression Stops

dive planning

Now that we understand the importance of adhering to decompression stops, let’s delve into some practical tips for diving without decompression stops.

Effective dive planning plays a crucial role in preventing the need for decompression stops by enabling divers to manage their profiles within nitrogen loading limits.

Safety stops, especially for dives deeper than 33 feet (10 m), facilitate the off-gassing of nitrogen, thereby reducing the risk of decompression sickness and eliminating the necessity for decompression stops.

Dive computers aid in preventing the need for decompression stops by:

  • Dynamically calculating no-decompression limits based on different compartments being the controlling compartment
  • Providing essential information on dive time, depth, and no-decompression time
  • Including ascent rate monitors to ensure a gradual and safe ascent, thereby reducing the risk of decompression sickness and eliminating the necessity for decompression stops.

Planning Your Dive

Careful planning of depth and time is vital to reduce the need for decompression stops.

For instance, engaging in shallow dives at depths like 6-10 meters (20-30 feet) makes it possible to enjoy prolonged underwater experiences without the need for a decompression stop. It is crucial to:

  • Carefully plan any potential decompression stops
  • Adhere to the no-stop/no-decompression limits
  • Incorporate safety stops as a standard procedure for dives deeper than 33 feet (10 m).

Dive computers offer real-time calculations for maximum dive time based on current depth and nitrogen levels, while tables assist in determining safe dive durations and surface intervals for specific depths.

Monitoring Your Dive

Keeping track of your dive with a dive computer or tables is critical to complying with the NDLs. A dive computer offers essential data, including:

  • Depth
  • No-decompression limits
  • Time
  • No stop time remaining (indicative of no-decompression limits)
  • Ascent rate
  • Emergency decompression
  • Previous dive information
  • Low battery warning

To accurately interpret this data, it is crucial for a diver to utilize a dive computer with a sizable and clear display and comprehend the manner in which the computer conveys its information.

Dive computers facilitate real-time monitoring to ensure the diver is aware of critical dive parameters at all times.

Dive tables, on the other hand, serve the purpose of providing charts that outline the maximum dive time for specific depths, which divers consult before and during the dive to ensure their planned dive profile stays within safe limits and avoids exceeding their NDL.

Dealing with Emergency Situations

Even with meticulous planning and monitoring, emergencies can still happen.

Hence, it’s vital to comprehend how to manage emergency situations during diving, which includes emergency decompression procedures and first aid for decompression sickness.

A decompression emergency during diving can be identified by observing any signs or symptoms of decompression illness within 24 hours of surfacing from a dive.

In these situations, initial first aid recommended for decompression sickness involves supplying 100% oxygen and keeping the oxygen flow during transfer.

First Aid for Decompression Sickness

Recognizing the signs of decompression sickness and administering first aid promptly can save a life.

The recommended initial first aid for decompression sickness involves administering 100% oxygen and maintaining oxygen supply during transfer.

The immediate administration of 100% oxygen helps reduce bubbles in the bloodstream and enhances oxygen delivery to affected tissues, thereby expediting recovery while awaiting professional medical treatment.

Seeking immediate professional medical help is crucial following the application of first aid measures for decompression sickness as it enables accurate assessment and administration of suitable treatment, including recompression in a hyperbaric chamber with hyperbaric oxygen therapy (HBOT).

The Limits of Recreational Diving

As we delve further into the intricacies of diving safety, understanding the depth limits established by various dive agencies for recreational diving becomes imperative.

These limits are set to uphold safety standards, as deeper dives elevate the risk of decompression sickness and necessitate more comprehensive training to address potential difficulties.

PADI Depth Limits

PADI has established depth restrictions for recreational diving at 18 meters/60 feet for the Open Water Course and up to 40 meters/130 feet for Advanced Open Water divers.

BSAC Depth Limits

BSAC (The British Sub-Aqua Club) has set depth limits for recreational diving, permitting Ocean Divers to dive to 20 meters and allowing Sports Divers to advance to a depth of 40 meters (130 feet).

These limits are designed to reduce the requirement for decompression stops, ensuring divers can ascend without needing mandatory decompression stops, staying within their No Decompression Limit.


As we ascend to the surface from our deep dive into the world of scuba diving safety, it’s clear that understanding the concept of no-decompression diving is essential in order to ensure a divers safety.

Adhering to no-decompression limits, utilizing dive tables and computers, differentiating between safety stops and decompression stops, and knowing how to handle emergency situations can significantly reduce the risk of decompression sickness.

Furthermore, being aware of the depth limits set by diving agencies and adhering to them can further ensure safety.

Frequently Asked Questions

How deep can you dive before you have to worry about the bends?

You should start to worry about the bends if you dive deeper than 30 feet, especially if you spend more than 30 minutes in the water at that depth. Keep in mind the risk increases the deeper and longer you dive.

Can you get the bends in 10 feet of water?

Yes, it is possible to get the bends in 10 feet of water, as the shallowest depth for a single dive producing bends symptoms was ten feet. Always ascend slowly and safely to reduce the risk of decompression sickness.

How deep can you scuba dive before being crushed?

The theoretical limit for human body pressure underwater is 1000 m, but no human has tested or reached this depth. The current record for deep diving is 600 m, achieved by a French diver in 2014.

What is no decompression limit?

The no decompression limit (NDL) is the maximum amount of time a diver can stay at a certain depth without needing to make decompression stops during ascent.

What is decompression sickness?

Decompression sickness occurs when nitrogen forms gas bubbles in the body due to pressure changes during diving. It can lead to serious health issues if not treated promptly.

Picture of Gia Halliday

Gia Halliday

Hey, my names Gia! My biggest passions are food, travel and basically anything to do with being in the water. Combine all of that with an addiction for buying gear and you end up with with this website!