What is the dual algorithm in Oceanic computers? And how does it change the way you dive?
These are two very important questions. Over the years, there have been confusing articles and discussions about how the algorithm in a dive computer works and what impact it has on the course of your dive.
Let's take a closer look at algorithms. Dive computers record the depth and time of a dive and use these measurements with an algorithm to determine no-decompression limits and decompression time. Algorithms are created by scientists who collect a large amount of dive data, average it, and conduct research. Most new algorithms are based on already existing models, in which modifications are made to adapt them to a specific type of diving. New algorithms can also be a combination of different models, making it possible to increase dive time and safety.
Currently, every model of Oceanic dive computer produced has not one, but two algorithms built-in. One is used for longer, deeper dives with a longer surface interval, while the other is for repetitive dives with a shorter surface interval. You choose which algorithm you want to use depending on the type of dive you are doing. You can also choose an algorithm that is consistent with your dive buddy's computer algorithm.
These two algorithms are based on different models:
Let's look at real-life scenarios:
Liveaboard dive safari (recreational diving). After a week of repetitive dives to a depth of 30 meters, a diver may be so saturated with nitrogen that their computer starts showing a shorter and shorter no-decompression time. Frequent dives and short surface intervals mean that the diver does not remove enough nitrogen from the body between dives, which affects the time of subsequent dives. The Pelagic DSAT algorithm was created precisely for such situations – frequent dives to a maximum depth of 30 meters. A diver using a computer with this algorithm will notice that after a few days on safari, it gives a longer time compared to computers from other manufacturers.
The chart below shows how well this algorithm is adapted to shallower dives. At a depth of 30 meters, all computers show a similar no-decompression time, but upon ascending to a depth of 18 meters, the computer with the Pelagic DSAT algorithm starts to show longer times. At a depth of 12 meters, the no-decompression time will be significantly longer than when using another computer or the Pelagic Z+ algorithm in an Oceanic computer.
Diving during a single day or on a weekend. Most of us work during the week and dive on weekends. This means we want to make the most of these two precious days and perform dives with maximum bottom time, for example, on a favorite wreck. The Pelagic Z+ algorithm is excellent for deeper dives in more challenging conditions, such as low temperatures. Most often, we also have a longer surface interval to eat something, warm up, and talk about the dive. The algorithm takes this into account to safely provide you with the most bottom time underwater. Pelagic Z+ generates profiles similar to the algorithms in Suunto and Mares computers.
Oceanic dive computers give you a choice depending on the dive you are doing. If you are doing shallower, repetitive dives over several days, the Pelagic DSAT algorithm works better, while for deeper dives with longer surface intervals, you will benefit more from using the Pelagic Z+ algorithm.
Article prepared by www.simplyscuba.com
These are two very important questions. Over the years, there have been confusing articles and discussions about how the algorithm in a dive computer works and what impact it has on the course of your dive.
Let's take a closer look at algorithms. Dive computers record the depth and time of a dive and use these measurements with an algorithm to determine no-decompression limits and decompression time. Algorithms are created by scientists who collect a large amount of dive data, average it, and conduct research. Most new algorithms are based on already existing models, in which modifications are made to adapt them to a specific type of diving. New algorithms can also be a combination of different models, making it possible to increase dive time and safety.
Currently, every model of Oceanic dive computer produced has not one, but two algorithms built-in. One is used for longer, deeper dives with a longer surface interval, while the other is for repetitive dives with a shorter surface interval. You choose which algorithm you want to use depending on the type of dive you are doing. You can also choose an algorithm that is consistent with your dive buddy's computer algorithm.
These two algorithms are based on different models:
- Pelagic DSAT – this algorithm is based on research that was used to create the PADI Recreational Dive Planner (RDP), used by thousands of divers around the world. Oceanic and other computer manufacturers have been using this algorithm for many years.
- Pelagic Z+ – this algorithm was created to safely extend dive time at a given depth, even when performing repetitive dives. It takes into account the influence of factors such as cold water and the effort made by the diver. This algorithm uses the same database as the Buhlmann ZHL-16C algorithm and generates dive profiles similar to those created by algorithms in dive computers from other manufacturers.
Let's look at real-life scenarios:
Liveaboard dive safari (recreational diving). After a week of repetitive dives to a depth of 30 meters, a diver may be so saturated with nitrogen that their computer starts showing a shorter and shorter no-decompression time. Frequent dives and short surface intervals mean that the diver does not remove enough nitrogen from the body between dives, which affects the time of subsequent dives. The Pelagic DSAT algorithm was created precisely for such situations – frequent dives to a maximum depth of 30 meters. A diver using a computer with this algorithm will notice that after a few days on safari, it gives a longer time compared to computers from other manufacturers.
The chart below shows how well this algorithm is adapted to shallower dives. At a depth of 30 meters, all computers show a similar no-decompression time, but upon ascending to a depth of 18 meters, the computer with the Pelagic DSAT algorithm starts to show longer times. At a depth of 12 meters, the no-decompression time will be significantly longer than when using another computer or the Pelagic Z+ algorithm in an Oceanic computer.
Diving during a single day or on a weekend. Most of us work during the week and dive on weekends. This means we want to make the most of these two precious days and perform dives with maximum bottom time, for example, on a favorite wreck. The Pelagic Z+ algorithm is excellent for deeper dives in more challenging conditions, such as low temperatures. Most often, we also have a longer surface interval to eat something, warm up, and talk about the dive. The algorithm takes this into account to safely provide you with the most bottom time underwater. Pelagic Z+ generates profiles similar to the algorithms in Suunto and Mares computers.
Oceanic dive computers give you a choice depending on the dive you are doing. If you are doing shallower, repetitive dives over several days, the Pelagic DSAT algorithm works better, while for deeper dives with longer surface intervals, you will benefit more from using the Pelagic Z+ algorithm.
Article prepared by www.simplyscuba.com
